Interior designer fee models and contracts: how US designers charge in 2026 and what a design agreement must contain

How do interior designers in the United States charge for their work?

Interior designers in the United States charge in four models, hourly, flat fee, percentage of project cost and cost-plus markup, and most established studios combine two of them, for example a flat design fee for concept work plus cost-plus on purchasing. Houzz Pro's guide to pricing design services, written for its own trade users, lists those four plus retail-price compensation (the designer keeps the retailer's trade discount) and "combination rates" that mix two or more structures. The Houzz guide gives formulas rather than prices: a flat fee equals estimated hours times the hourly rate, a cost-plus fee equals products plus subcontractors plus the agreed percentage, and a square-foot fee equals the rate times the area.

The two consumer price guides retrieved for this article disagree on the hourly range because they sample different markets. Thumbtack's interior designer cost guide, last updated June 30, 2025, draws on requests placed through its marketplace and reports a national average project cost of $1,103 within a typical range of $494 to $2,460. Decorilla's cost guide dated August 9, 2026 covers full-service and online design and reports $2,000 to $15,000 for a traditional project excluding furniture.

Key figure: hourly rates of $60 to $125 (Thumbtack, June 2025) or $100 to $500 (Decorilla, August 2026); percentage fees of 15% to 25% or 10% to 30%; cost-plus markups of 15% to 35% or about 20%.

What do the four fee models cost in 2025 and 2026?

Hourly billing ran $60 to $125 per hour in Thumbtack's June 2025 data and $100 to $500 per hour in Decorilla's August 2026 data; flat fees ranged from $1,500 to $5,000 for smaller residential projects up to $10,000 to $50,000 or more for larger ones (Decorilla); percentage fees were 15% to 25% of the budget (Thumbtack) or 10% to 30% (Decorilla); and cost-plus markups were 15% to 35% of item cost (Thumbtack) or around 20% (Decorilla). Per-square-foot pricing, used mostly in commercial and hospitality work, ran $4 to $17 (Thumbtack) or $5 to $20 or more (Decorilla).

Fee model	Thumbtack (updated June 30, 2025)	Decorilla (August 9, 2026)
Hourly	$60 to $125 per hour	$100 to $500 per hour
Flat fee	Example: $10,000 per project	$1,500 to $5,000 small; $10,000 to $50,000+ large
Percentage of project cost	15% to 25% of budget or amount spent	10% to 30% of total budget
Cost-plus markup	15% to 35% of product or item cost	Around 20% on furnishings and supplies
Per square foot	$4 to $17	$5 to $20 or more (commercial, hospitality)
Initial consultation	$350 to $500	Not stated
Online design package	Not stated	$159 to $2,099 flat

The same $40,000 furnishing budget produces very different fees under each model. At 20% cost-plus the designer earns $8,000 on purchasing alone; at a 15% percentage-of-project fee on a $40,000 total the fee is $6,000; at $125 per hour the same $6,000 buys 48 hours of design time. Clients who compare proposals should convert every model to an estimated dollar total for the same scope before choosing.

Hourly and flat-fee models make the client's cost independent of what is bought, while percentage and cost-plus models rise with the budget. Houzz Pro's cost-plus guide, published July 27, 2021, states the model plainly: the designer's compensation is the agreed percentage over the cost of products and subcontractors, and it names the Houzz trade program discount as one source of the goods a designer supplies. The choice matters most on projects where furnishings dominate, which is why the ASID contract separates purchasing services from design services.

When does each fee model fit the project?

Hourly billing fits consultations, small scopes and projects with an open-ended scope, flat fees fit defined scopes such as a concept package for one room, percentage fees fit renovations where the designer coordinates contractors as well as furnishings, and cost-plus fits projects where procurement is the main service. The 2018 ASID commercial contract user guide organizes its fee options around exactly that split, with separate compensation structures for design services, procurement and project administration.

• Hourly: predictable rate, unpredictable total. Thumbtack's $60 to $125 band suits consultations and short scopes; Decorilla's $100 to $500 band covers senior designers on complex projects.
• Flat fee: predictable total, fixed scope. Decorilla's $1,500 to $5,000 for smaller residential projects assumes a written scope; changes trigger additional fees.
• Percentage of project cost: aligns the fee with a construction budget the designer manages, at 10% to 30% (Decorilla) or 15% to 25% (Thumbtack).
• Cost-plus: transparent on paper, dependent on disclosure of the base cost, at 15% to 35% (Thumbtack) or about 20% (Decorilla).
• Combination: ASID's own fee tables pair a fixed design fee with a procurement fee calculated as a percentage of FF&E cost.

Registration status changes what can be priced. In Florida, only a registered interior designer may practice commercial interior design, and in the states with permitting privileges a registered designer may seal non-structural permit drawings; that work is billed as construction-document scope, usually by the hour or as a flat phase fee. The state rules are in the article on interior design license requirements by state.

What must an interior design contract contain?

An interior design agreement must define the parties and the project, the services in each phase, how merchandise is selected and purchased, who administers the project, how the designer is paid, the terms of sale for goods, how either party may terminate, and how disputes are resolved, which is the structure of the ASID Interior Design Residential Contract Package. The package page lists a core letter agreement and eleven schedules, authored by Alan M. Siegel, Hon. FASID, of Levy Sonet and Siegel LLP.

ASID residential schedule	Subject	Options offered
A	Preliminary Project Information	One
B	Design Concept Services	One
C	Selection of Merchandise	One
D	Purchasing Services	Five
E	Project Administration Services	One
F	Designer Compensation	Nine
G	Terms and Conditions of Sale	One (governs client purchases)
H	Termination Rights	One
I	Dispute Resolution	Two
J	Additional Terms and Conditions	One
K	Blank schedule for customization	One

The commercial package follows the same logic with different content. Its 2018 user guide lists Schedule D for interior construction related design services, Schedule E for FF&E selection and specification, Schedule F for project administration, two versions of Schedule G for purchasing services, eight versions of Schedule H for designer compensation, Schedule I for termination rights with optional termination fee clauses, and Schedule J with two dispute options: J-1 litigation with optional mediation and J-2 arbitration with optional mediation. The guide's fee tables map those schedules to a fixed design fee, a fixed fee plus a procurement fee calculated as a percentage of FF&E cost, an hourly fee for all services, and hourly plus procurement combinations.

ASID's contracts page quotes the author's position that "every interior designer must enter into a written agreement with a client; it shouldn't be an optional activity," prices each package at $349 ($249 for members) and the combined set at $698 ($498 with the member code), and recommends a local attorney review because contract law differs by state. Each purchase is a one-year license.

Key figure: 11 schedules in the ASID residential contract, 9 compensation options, 5 purchasing options and 2 dispute-resolution options; $249 for members, $349 for non-members.

What should a client check before signing a design agreement?

A client should check nine items before signing: the fee model and its dollar estimate for the stated scope, the hourly rate and who bills at it, the deposit or retainer and whether it is credited, the markup or discount treatment on purchases, the number of revisions included, the change-order procedure, the termination terms and any termination fee, the dispute clause (litigation or arbitration), and the designer's registration number where the state requires one. Every one of those items maps to a schedule in the ASID package.

1. Fee model and estimate: convert hourly, percentage or cost-plus terms to a dollar figure for the same scope.
2. Rates by person: senior and junior staff often bill at different hourly rates.
3. Deposit or retainer: the ASID schedules treat compensation and merchandise deposits separately.
4. Purchasing terms: whether trade discounts pass through and what percentage is added (15% to 35% in Thumbtack's 2025 data).
5. Revisions and change orders: flat fees assume a fixed scope.
6. Project administration: whether site visits and contractor coordination are included or billed hourly.
7. Termination: notice period and whether a termination fee applies.
8. Disputes: litigation or arbitration, and whether mediation comes first.
9. Credentials: NCIDQ certificate status and, in Florida commercial work, Louisiana, Nevada or DC, the state registration.

A designer's overhead explains part of the fee. Association dues of $549 (ASID) or $599 (IIDA) per year and a software stack that can run from $45 per month for AutoCAD LT to $109 per user per month for Studio Designer are itemized in the article on ASID and IIDA membership and software costs. The wage side of the profession, a $67,190 national median for salaried designers in May 2025, is covered in the article on interior designer salary by state, and it sets a floor under what a self-employed designer must bill to match an employed peer.

How do online and traditional design services compare on price?

Online interior design services sold flat packages from $159 to $2,099 per room in Decorilla's August 2026 guide, while traditional full-service design ran $2,000 to $15,000 per project excluding furniture, a gap driven by the absence of site visits, procurement management and contractor coordination in the online model. Thumbtack's June 2025 marketplace data, which mixes decorators, stagers and designers, sits in between with a $1,103 average and a $494 to $2,460 typical range.

The online model is a flat-fee model by construction: a fixed deliverable (concept board, floor plan, shopping list) for a fixed price, with purchasing left to the client or routed through affiliate links. Clients who want the designer to manage a renovation, seal permit drawings or place trade orders will not find those services in a $159 package, and the fee models for that work return to the hourly, percentage and cost-plus structures above.