How Do You Open an Interior Design Business?

Is your interior design business truly maximizing its profit potential? Discover nine strategic approaches designed to elevate your firm's financial performance, from optimizing project management to enhancing client acquisition. Explore how a robust financial framework, like the one offered by this comprehensive interior design store financial model, can underpin your growth and ensure sustainable success.

Steps to Open a Business Idea

Embarking on the journey of launching an interior design business requires careful planning and execution. The following table outlines essential steps to guide aspiring entrepreneurs through the foundational stages, ensuring a robust start for their venture.

Step Description
Step 1: Define Your Niche And Business Model Define your specialized niche (e.g., luxury, sustainable) and service model (e.g., full-service, e-design) to differentiate your brand and target higher profits.
Step 2: Create A Comprehensive Business Plan Develop a comprehensive business plan detailing your mission, market analysis, and financial projections, essential for growth and securing funding.
Step 3: Handle Legal And Financial Formalities Register your business, obtain an EIN, open a business bank account, secure necessary licenses, and acquire business insurance to protect your assets.
Step 4: Build Your Professional Brand Identity Create a memorable brand name, logo, and professional online presence with a high-quality portfolio website and curated social media profiles.
Step 5: Develop Supplier And Contractor Relationships Establish accounts with reliable trade-only suppliers and build a network of trusted contractors to access wholesale pricing and ensure smooth project execution.
Step 6: Implement Marketing And Client Acquisition Strategies Develop a multi-channel marketing plan, including digital marketing and referral programs, to acquire clients and generate leads effectively.
Step 7: Set Up Operational Systems And Technology Implement project management tools and design software (e.g., CAD, 3D rendering) to enhance productivity, manage clients, and optimize financial operations.

What Are Key Factors To Consider Before Starting Interior Design?

Starting an Interior Design business, such as Interior Innovators, requires careful consideration of several key factors to ensure long-term profitability and success. These include defining a niche market, creating a detailed business plan focused on interior design profitability strategies, and securing adequate startup capital.

The US interior design market was valued at $241 billion in 2023 and is projected for continued growth. Developing a niche market for higher interior design profits is crucial. Specializing in areas like biophilic design or tech-integrated homes allows firms to capture a more lucrative client base. Specialized services can command fees 15-25% higher than general design work, directly impacting interior design firm financial success.

A comprehensive business plan is essential for any new venture, especially for an Interior Design business like Interior Innovators, which merges product retail with design services. Startup costs for an Interior Design business with a retail component can range from $50,000 to over $150,000. These costs cover initial lease agreements, inventory for curated selections, and marketing efforts to attract the target audience. Financial planning and budgeting for interior design firms must account for recurring expenses. For example, professional design software like AutoCAD costs approximately $2,375 per year, and professional insurance (Errors & Omissions) typically ranges from $1,200 to $2,200 annually.


Key Financial Considerations for Launching an Interior Design Business:

  • Capital Requirements: Startup costs can exceed $150,000 for a retail-integrated model.
  • Software Costs: Budget for essential tools like AutoCAD at $2,375/year.
  • Insurance Needs: Allocate $1,200-$2,200/year for professional liability insurance.

Optimizing financial management for small interior design studios from the outset is vital for avoiding common pitfalls. According to a US Bank study, 82% of small businesses fail due to poor cash flow management. Securing adequate initial capital, potentially through an SBA 7(a) loan, can provide a necessary buffer. Average SBA 7(a) loan amounts have been around $420,000 in recent years, which can cover operational expenses for the first 18-24 months. This strategic financial backing supports the transformation of ideas into investor-ready ventures. For more insights on financial planning, refer to resources like Interior Design Store Profitability.

How To Boost Interior Design Revenue?

To effectively boost interior design revenue, an Interior Design firm must diversify its income streams, implement strategic pricing models, and master client acquisition for high-value projects. These core areas are crucial for sustained interior design business growth.


Diversifying Income Streams

  • Diversifying income streams for interior design professionals is a core component of growth. Beyond service fees, integrating retail sales of curated furniture and decor can add a significant revenue channel. Typical industry markups on products range from 25% to over 100% (keystone pricing). For example, if a firm purchases a sofa for $1,000 and sells it to the client for $2,000, that's a 100% markup, directly increasing profitability.
  • Expanding into product sales, as envisioned by Interior Innovators, allows for multiple revenue touchpoints beyond just design fees. This approach transforms a service-only model into a more robust business with direct product sales contributing to the bottom line.

Employing the right interior design pricing models is critical for profitability. While the national average hourly rate for interior designers is around $150, successful firms often use a hybrid model. This can involve a flat fee for design concepts, typically ranging from $5,000 to $15,000 per room, combined with a percentage (15-30%) on furniture and materials. This hybrid approach is one of the best business practices for interior designers to make more money, ensuring fair compensation for both design expertise and product procurement.

Expanding service offerings for interior designers to earn more also provides significant revenue opportunities. E-design packages, for instance, represent a market segment growing at over 10% annually, allowing designers to reach a broader client base without extensive travel. Virtual Reality (VR) consultations are another premium service, which can be billed at a premium of 20-30% over standard consultation fees. These tech-driven services enhance client experience and command higher rates, contributing directly to interior design firm financial success. For more insights on financial performance, refer to Interior Design Store Profitability.

What Legal And Regulatory Steps Are Required To Open Interior Design?

Opening an Interior Design business, such as Interior Innovators, requires careful attention to legal and regulatory steps. The essential actions include registering your business entity, obtaining federal and state tax IDs, and securing the necessary state and local licenses. This foundational work ensures your firm operates legally and protects your personal assets, contributing to long-term interior design firm financial success.

Choosing the correct business structure is a foundational step. While over 70% of US small businesses operate as sole proprietorships, forming an LLC (Limited Liability Company) is a common strategy to protect personal assets from business liabilities. The filing fees for an LLC vary by state, typically costing between $50 and $500. Additionally, a federal Employer Identification Number (EIN) is required for most business types, including those with employees, and is free from the IRS. This EIN is crucial for tax purposes and opening a business bank account.


Key Licensing Requirements for Interior Designers

  • State Licensing: Currently, 27 states and the District of Columbia have laws regulating the interior design profession. States like Florida and Nevada require designers to pass the NCIDQ (National Council for Interior Design Qualification) exam for certain projects. Practicing without the proper credentials in regulated states can lead to significant fines, potentially up to $5,000 per offense.
  • General Business Licenses: Beyond professional licensing, a general business operating license is required in most cities and counties. Annual fees for these licenses typically range from $50 to $400, depending on the municipality.
  • Seller's Permits/Resale Licenses: If your Interior Design business plans to sell tangible goods, like Interior Innovators' model of merging product retail with design services, you must obtain a seller's permit or resale license from your state's tax agency. This allows you to purchase goods wholesale without paying sales tax, collecting it instead from your customers. Understanding these requirements is vital for increasing interior design profits through diversified income streams. For more details on financial aspects, consider resources like Interior Design Store Profitability.

Securing comprehensive business insurance is also critical. This typically includes general liability insurance, which protects against claims of bodily injury or property damage, and professional liability (Errors & Omissions) insurance, which covers negligence or mistakes in your design services. These policies mitigate risks and provide peace of mind, allowing you to focus on client acquisition and interior design business growth.

What Is A Good Profit Margin For An Interior Design Business?

A healthy net profit margin for a well-run Interior Design business, such as Interior Innovators, typically falls between 20% and 30%. This metric is crucial for tracking overall interior design business growth. For new studios, achieving a 10-15% net profit margin in the first two years is considered a strong benchmark, indicating effective initial management and project delivery. Understanding these figures helps entrepreneurs set realistic financial goals and assess their firm's performance against industry standards.

Interior designers can significantly increase their profit margins by carefully managing project costs and reducing overhead costs in an interior design company. For example, a firm with $300,000 in annual revenue can directly add $15,000 to its net profit by achieving just a 5% reduction in overhead expenses. This highlights the direct impact of cost control on overall profitability. Streamlining operations and optimizing financial management are key to achieving these reductions, as detailed in resources like this article on interior design business profitability.

Negotiating better deals with suppliers for interior design projects directly impacts profitability. Securing an additional 10% trade discount on a project with a $100,000 furniture budget, for instance, adds a substantial $10,000 directly to the firm's bottom line. This significantly improves the profit margin for that specific project and the overall business. Building strong supplier relationships and leveraging purchasing power are essential strategies for boosting profitability.

Streamlining operations to boost interior design business efficiency also significantly widens margins. Implementing specialized project management tools for efficient design delivery, such as Studio Designer or DesignFiles, can reduce non-billable administrative hours by as much as 25-30%. These software subscriptions, typically ranging from $99-$199 per month, allow designers to manage clients, projects, and billing more effectively. This efficiency enables higher project capacity without increasing staffing, directly contributing to improved profitability and supporting the firm's ability to take on more high-value work.


Key Strategies for Higher Profit Margins:

  • Cost Management: Actively track and control project-specific expenses.
  • Overhead Reduction: Identify and cut unnecessary fixed costs within the business.
  • Supplier Negotiation: Leverage volume and relationships to secure better trade discounts.
  • Operational Efficiency: Adopt technology and streamlined processes to reduce non-billable hours.
  • Strategic Pricing: Implement pricing models that accurately reflect value and cover all costs, ensuring adequate markups.

How To Attract High-End Clients?

Attracting high-end clients for an Interior Design business requires a strategic approach focused on luxury branding, targeted networking, and showcasing an exceptional portfolio. These clients seek value and exclusivity, making brand perception critical. For instance, increasing profitability in an interior design business often links directly to securing higher-value projects from this demographic.


Key Strategies for High-End Client Acquisition

  • Build a Strong Luxury Brand Identity: Invest in a professional, high-end website, which typically costs between $7,000 and $20,000 for a custom build. Professional photography of completed projects is essential, as 93% of consumers cite visual appearance as a key purchasing factor. This strong brand foundation is a primary component of strategies to attract high-end clients for interior design.
  • Leverage Targeted Social Media: High-net-worth individuals are active on platforms like Instagram and LinkedIn. A 2023 report indicates that 79% of affluent consumers use social media to follow brands. Partnering with luxury influencers can cost from $1,000 to $10,000 per post but can yield a high return on investment, driving interior design business leads and sales.
  • Implement Effective Referral Strategies: Referrals are exceptionally powerful in the luxury market. Building strong relationships with architects, luxury real estate agents, and wealth managers creates a pipeline of qualified leads. A Nielsen study found that 92% of consumers trust referrals from people they know, making it the most effective form of marketing for interior design profit increase.

Step 1: Define Your Niche And Business Model

To significantly increase interior design profits, the foundational step involves clearly defining your niche and establishing a robust business model. This strategic clarity allows you to target specific clients effectively, optimize your service offerings, and differentiate your brand in a competitive market. Without a defined focus, businesses often struggle with inconsistent client acquisition and diluted marketing efforts, impacting their financial success.

Specializing in a target market is crucial for interior design business growth. For instance, focusing on luxury residential interior design allows for higher project fees and a more curated client experience. Alternatively, specializing in sustainable design appeals to an eco-conscious clientele, while commercial hospitality projects can offer larger scale and recurring business opportunities. This specialization helps in developing a niche market for higher interior design profits, attracting clients specifically seeking your expertise.

Determining your core service offerings is equally vital. This could range from full-service design, which encompasses every project stage from concept to installation, to more streamlined e-design services, which are often delivered remotely and at a lower price point. A hybrid model, like that of Interior Innovators, merges product retail with personalized design services, empowering customers to express individuality through curated selections and expert guidance. This diversification of income streams for interior design professionals helps cater to a broader client base while maintaining profitability.


Developing Your Unique Value Proposition

  • Identify Client Problems: Understand specific challenges your target clients face, such as creating stylish, functional spaces or navigating complex renovation projects.
  • Highlight Differentiation: Clearly articulate what makes your interior design business unique compared to competitors. This could be a specific design aesthetic, a streamlined process, or unparalleled client support.
  • Focus on Solutions: Your value proposition should explain how your services provide direct solutions, transforming houses into homes or optimizing commercial spaces for efficiency and appeal.

Establishing a unique value proposition is essential for attracting high-end clients for interior design and building a targeted brand. Your unique value proposition should clearly state what problem you solve for your target client and what makes you different. For example, Interior Innovators aims to revolutionize the interior design shopping experience by merging product retail with personalized design services, directly addressing common homeowner challenges. This initial focus is a crucial step towards developing a niche market for higher interior design profits and building a targeted brand that resonates with your ideal client base, significantly boosting interior design revenue.

Step 2: Create A Comprehensive Business Plan

Developing a comprehensive business plan is fundamental for any aspiring or established entrepreneur, especially in the dynamic interior design sector. This document serves as your strategic roadmap, guiding every decision and action. It clearly outlines your company's mission, vision, and organizational structure. For an interior design firm like Interior Innovators, setting clear short-term and long-term goals for interior design business growth is crucial. This proactive planning helps you define where you want your business to be in the next one, three, and five years, ensuring focused efforts and efficient resource allocation towards achieving those milestones.

A critical component of your business plan involves conducting a thorough market analysis. This step requires identifying your precise target audience within the US interior design industry, understanding their needs, preferences, and purchasing power. Simultaneously, you must analyze your competitors to understand their strengths, weaknesses, and market positioning. Researching current market trends, such as the increasing demand for sustainable design or smart home integration, allows you to identify opportunities and potential challenges. For example, understanding that the average homeowner spends approximately $5,000 to $15,000 on interior design projects can help in setting realistic revenue targets and service pricing.

Your business plan must also include a detailed financial section. This part covers essential elements like startup cost estimates, which for a new interior design studio could range from $10,000 to $50,000, depending on location and initial inventory. It should project revenue for the first three to five years, incorporating strategies to boost interior design revenue through various service offerings. A crucial element is the break-even analysis, which determines the sales volume needed to cover all costs. This financial blueprint is not just for internal guidance; it is absolutely essential for securing investor funding or bank loans, demonstrating your firm's potential for interior design firm financial success.


Key Elements of an Interior Design Business Plan

  • Executive Summary: A concise overview of your entire plan, highlighting the core aspects of your interior design business.
  • Company Description: Details about Interior Innovators' legal structure, mission, vision, and values, emphasizing its unique approach to design and retail.
  • Services and Products: A comprehensive list of design services offered and product categories available, detailing how they address client needs and contribute to interior design profitability strategies.
  • Marketing and Sales Strategy: How you plan to attract and retain clients, including digital marketing, networking, and referral programs to increase client acquisition for interior design.
  • Management Team: Profiles of key personnel, their experience, and roles within the firm, demonstrating the expertise driving interior design business growth.
  • Financial Projections: Detailed forecasts including income statements, cash flow projections, and balance sheets, essential for tracking interior design firm financial success and securing funding.

Step 3: Handle Legal And Financial Formalities

Why is Business Registration Crucial for Interior Design Firms?

Registering your Interior Design business formally protects personal assets and establishes credibility. For example, registering as a Limited Liability Company (LLC) or S-Corporation legally separates your personal finances from the business, meaning personal assets are protected if the business faces legal claims or debts. This is a foundational step for any aspiring entrepreneur, particularly for a service-based business like Interior Innovators, which aims to merge product retail with design services. Formal registration also allows you to legally operate, open business bank accounts, and apply for necessary permits, streamlining financial management for small interior design studios.

How to Obtain Essential Business Identification Numbers and Accounts?

Securing a Federal Employer Identification Number (EIN) is a critical step for tax purposes and financial management. An EIN acts like a Social Security number for your business, required for hiring employees, filing taxes, and opening a dedicated business bank account. For Interior Innovators, a separate business bank account is essential to manage revenue from design services and product sales effectively. This separation simplifies financial tracking, makes tax preparation easier, and projects a professional image to clients and suppliers. This practice is key to optimizing financial management for small interior design studios and ensuring your interior design business growth.


What Licenses and Permits Do Interior Design Businesses Need?

  • Federal Licenses: While federal licenses are rare for interior design, ensure compliance if you plan to import specific products for your retail component.
  • State Licenses: Many states require specific licenses for interior designers, often involving educational or experience qualifications. For example, some states require a professional interior design license to use the title 'certified interior designer.' Research your specific state's Board of Professional Regulation or similar body.
  • Local Permits: City and county permits are common, including general business licenses, zoning permits, and potentially a seller's permit (resale certificate) if Interior Innovators plans to retail products, allowing you to purchase goods without paying sales tax for resale.
  • Sales Tax Permit: If selling products, a sales tax permit is mandatory to collect and remit sales tax to your state.

Why is Business Insurance Essential for Interior Design Firms?

Comprehensive business insurance mitigates significant financial risks for interior design firms. General liability insurance protects against claims of bodily injury or property damage occurring on your business premises or due to your operations. Professional liability insurance, also known as Errors & Omissions (E&O) insurance, is crucial for interior designers. This covers claims of negligence, errors, or omissions in your professional services, such as design flaws or advice that leads to client losses. For Interior Innovators, which combines design services with product retail, both types of insurance are vital to protect against diverse risks, from a client slipping in your showroom to a design error causing structural issues. Securing the right insurance is a key strategy to increase interior design profits by protecting against unforeseen legal costs and damages.

Step 4: Build Your Professional Brand Identity

A strong brand identity is crucial for interior design business growth and attracting your ideal clientele. It helps differentiate your firm, Interior Innovators, in a competitive market and establishes immediate recognition. Developing a professional brand image ensures consistency across all client touchpoints, building trust and perceived value, which directly impacts interior design profitability strategies.

Developing Core Brand Elements

  • Brand Name and Visuals: Create a memorable brand name, logo, and a consistent color palette. These elements should reflect your specific niche, such as modern minimalist or classic luxury, and appeal directly to your target clientele. For example, if aiming for high-end residential projects, your visuals should convey sophistication and exclusivity.
  • Online Presence: Establish a high-quality portfolio website. This digital hub is essential for showcasing your work and is often the first point of contact for potential clients. Complement your website with curated social media profiles on visual platforms like Instagram and Pinterest, which are vital for interior design marketing strategies and client acquisition interior design.

Professional photography of your completed projects is your most powerful marketing asset. High-resolution images that capture the essence and quality of your work are non-negotiable for client acquisition interior design. Studies show that visuals are processed 60,000 times faster than text, making compelling imagery critical for engaging potential clients and demonstrating your capabilities. This investment directly supports your efforts to boost interior design revenue.

Finally, design and print professional marketing materials. This includes business cards, brochures, and client presentation templates. Maintaining consistent branding across all these items reinforces your professional image and ensures every interaction reflects your established identity. These materials should be designed to leave a lasting impression, supporting your goal of increasing interior design profits by attracting and converting quality leads.

Step 5: Develop Supplier And Contractor Relationships

Building strong supplier and contractor relationships is fundamental for increasing interior design profits. For an interior design business like Interior Innovators, accessing wholesale pricing and ensuring high-quality project execution directly impacts financial success. Establishing accounts with trade-only suppliers for furniture, lighting, textiles, and accessories is crucial. This allows for significant cost savings compared to retail prices, directly boosting profit margins on product sales. Reliable suppliers ensure consistent quality and timely deliveries, which are vital for efficient project management and client satisfaction.


Key Steps to Cultivate Profitable Partnerships

  • Identify Trade-Only Suppliers: Research and establish accounts with suppliers who offer wholesale pricing exclusively to the trade. This is a primary strategy to increase profit margins in an interior design firm.
  • Build a Trusted Contractor Network: Develop relationships with skilled painters, electricians, plumbers, and carpenters. Their quality of work must consistently meet your interior design business standards. This network streamlines operations to boost interior design business efficiency.
  • Implement Order Management Systems: Create a clear system for tracking orders, lead times, and deliveries. Efficient management ensures projects run smoothly and on schedule, reducing costly delays.
  • Negotiate Better Deals: Actively negotiate with suppliers for interior design projects. This is a key lever for improving profit margins on both goods and services, directly impacting your interior design firm's financial success.

Effective negotiation with suppliers is a powerful strategy for profitable interior design projects. By securing better pricing on materials and products, Interior Innovators can enhance overall profitability. For instance, a 5-10% reduction in material costs through negotiation can significantly increase the profit margin on a typical residential project. This directly contributes to how interior designers increase their profit margins. Developing a robust network of trusted contractors also ensures that labor costs are competitive and project timelines are met, preventing budget overruns and improving client satisfaction, which supports long-term interior design profitability and client retention.

Step 6: Implement Marketing And Client Acquisition Strategies

Develop a Multi-Channel Marketing Plan for Interior Design Growth

To effectively acquire clients and increase interior design profits, a comprehensive multi-channel marketing plan is essential. This approach ensures your business reaches potential clients across various platforms, maximizing visibility. A robust plan integrates digital marketing, content creation, social media engagement, and local search engine optimization (SEO). For instance, Interior Innovators can use digital ads targeting homeowners interested in home decor, coupled with blog posts offering design tips. This broad reach helps attract a diverse client base, from first-time founders seeking guidance to seasoned entrepreneurs looking for streamlined solutions.

Implement Effective Marketing Techniques for Profitable Interior Design Projects

Focus on marketing techniques proven to generate leads and secure profitable projects. Creating a lead-generating blog, for example, establishes your expertise and attracts organic traffic. Showcasing your portfolio on visual platforms like Houzz and Pinterest is crucial, as 90% of consumers find visual content more engaging than text-based content. These platforms allow potential clients to visualize your style and the quality of your work, directly influencing their decision-making process. High-quality project showcases lead to more inquiries for high-end interior design projects.


Key Marketing Techniques for Interior Design

  • Lead-Generating Blog: Publish articles on topics like 'optimizing small spaces' or 'choosing sustainable materials' to attract organic search traffic.
  • Houzz and Pinterest Showcases: Curate stunning project photos with detailed descriptions and keywords to rank higher in searches for interior design inspiration.
  • Email Marketing: Build a subscriber list and send newsletters with design trends, project updates, or exclusive offers to nurture leads.
  • Google My Business Optimization: Ensure your local listing is complete and updated to appear in local search results for 'interior design near me.'

Establish a Referral Program to Boost Interior Design Profitability

Word-of-mouth marketing remains one of the most powerful and cost-effective client acquisition strategies for an interior design business. Implementing a structured referral program encourages past clients, contractors, and real estate professionals to recommend your services. Offering incentives, such as a discount on future services or a referral fee, motivates these advocates. A strong referral network can significantly increase profit margins in an interior design firm by reducing customer acquisition costs. Studies show that referred customers have a 37% higher retention rate, contributing to long-term profitability.

Network Strategically and Attend Industry Events for Client Acquisition

Active networking is vital for attracting new clients and building industry connections. Attend local business groups and interior design industry events to meet potential clients, collaborators, and referral partners. These interactions provide opportunities to discuss your expertise, such as how Interior Innovators merges product retail with personalized design services. Strategic networking can lead to direct project leads, partnerships with complementary businesses (like architects or builders), and insights into new market opportunities. This direct engagement helps build a stronger brand identity for interior design business growth.

Step 7: Set Up Operational Systems And Technology

Establishing robust operational systems and integrating appropriate technology is crucial for an interior design business like Interior Innovators to achieve sustainable growth and profitability. Efficient systems streamline daily tasks, reduce errors, and free up time for creative work and client engagement. This focus directly contributes to increased interior design profits by enhancing productivity and client satisfaction.

For interior design firms, selecting the right tools impacts every aspect, from initial client contact to final project delivery. A well-structured operational framework ensures consistency, allowing the business to manage more projects without compromising quality. This approach supports the goal of optimizing financial management for small interior design studios, ensuring resources are utilized effectively.


Key Systems and Technology for Interior Design Businesses

  • Project Management Tools: Implement specialized software to manage projects efficiently. Tools like Mydoma Studio, Ivy, or Studio Designer are designed specifically for interior designers. They help manage clients, track project progress, organize tasks, and handle billing. Using these platforms ensures efficient design delivery and improves overall project oversight, directly impacting how to increase profit margins in an interior design firm.
  • Design Software Integration: Utilize advanced design software to enhance business productivity and create professional presentations. Programs such as CAD (Computer-Aided Design) software and 3D rendering tools like SketchUp or Chief Architect enable designers to visualize concepts accurately. This not only streamlines the design process but also helps attract high-end clients for interior design by showcasing detailed, realistic proposals.
  • Client Onboarding and Communication: Establish clear, systematic processes for client onboarding and ongoing communication. A seamless initial experience builds trust and sets positive expectations. This includes structured intake forms, clear contract explanations, and regular communication protocols. Effective client communication ensures a positive client experience from start to finish, which is vital for improving client retention for long-term interior design profitability and fostering referrals.
  • Financial Management Systems: Set up a robust financial management system using dedicated software. QuickBooks is a widely used solution for optimizing financial management for small interior design studios. This software helps track income and expenses, manage invoices, monitor key performance indicators (KPIs) such as profit margins and overhead costs, and prepare financial reports. Accurate financial tracking is essential for informed decision-making and identifying areas to reduce overhead costs in an interior design company.