Design Only, Design + Construction and Turnkey: What Is the Difference?
Written by Nitipoom Dechwongya, Founder of Penthouse Design Group · Updated October 2026
Design Only means commissioning a design team and appointing a contractor separately. Design + Construction and Turnkey bring design and construction under one coordinated team, within the agreed contract scope. The difference is not simply who builds: it also concerns information handovers, contractual parties, cost control and the coordination workload required of the owner. No model is best for every project. Choose according to your availability, the complexity of the project and the contract details.
A quick comparison of three approaches
| Topic | Design Only | Design + Construction | Turnkey |
|---|---|---|---|
| Design | Design team | The construction team or an affiliated design team | Included within the agreed scope |
| Contractor | Selected by the owner | Delivered by the design-and-construction team | Managed by the lead provider under the contract |
| Parties the owner coordinates | More | Fewer | Often the fewest, depending on the contract |
| Flexibility to tender | High | Depends on the terms | Depends on pricing and inclusions |
| Design handover risk | Requires clear management | Can reduce handovers | Can reduce handovers when responsibilities are clear |
| What to check | Drawing package and construction-stage design services | BOQ, contract and approval responsibilities | Inclusions, exclusions and handover criteria |
Companies use Turnkey differently. Do not judge a package by its name alone. Always read the scope, deliverables, exclusions and variation terms.
Who is Design Only suitable for?
Design Only suits owners who want to appoint the designer and contractor separately, already have a trusted contractor, wish to obtain comparable quotations, or have a project-management team to coordinate the work.
Deliverables may include space planning, mood and tone, 3D visuals, material selection, construction drawings and supporting schedules, as defined in the proposal. Ask:
- How detailed are the drawings, and do they cover building services?
- Are material specifications and a BOQ included?
- How much support does the designer provide for contractor queries during construction?
- Are site inspections included, and how many?
- If site conditions require drawing revisions, who is responsible and how are fees assessed?
The advantage is flexibility in choosing a contractor. The owner must, however, clearly manage information handovers and responsibilities across the parties.
Who is Design + Construction suitable for?
This approach combines design and construction within one team or a coordinated group. It suits owners who want fewer handovers between drawings and site work, with construction-stage detail changes handled within a single workflow.
A single team does not automatically mean everything is included. Check who approves materials, controls quality and takes responsibility for building services, which documents you receive at completion, and how variations are priced.
What does Turnkey mean, and what else should you ask?
In general, Turnkey describes a lead provider managing several stages until a space is ready to use within a defined scope. Ready to use varies: some contracts include loose furniture, curtains, lighting or equipment, while others do not.
Before choosing Turnkey, request a clear list of inclusions and exclusions. At minimum, ask:
- Are demolition and remedial works to the existing space included?
- What level of electrical, plumbing, air-conditioning and specialist systems is included?
- Are loose furniture, appliances and decorative items included?
- Are approvals, building deposits, transport and out-of-hours working included?
- What are the acceptance criteria, warranty terms and handover documents?
Choose for your coordination needs, not price alone
Choose Design Only when
- You want to appoint a contractor separately
- You have a project team or time to coordinate several parties
- You want completed drawings for comparable quotations
- Construction-stage design services are clearly defined
Choose Design + Construction or Turnkey when
- You want fewer handovers between design and construction
- You want a clearly identified lead party
- Built-in elements and bespoke details need close coordination
- You accept the material selection, pricing and variation-approval process offered by the provider
Whichever approach you choose, the result depends on drawings, specifications, the BOQ, contract, site team and timely decisions, not the service name alone.
Documents to request before deciding
- Scope of work and deliverables
- Inclusions and exclusions
- Programme and key approval milestones
- Material Specification
- BOQ organised by work section and quantity
- How variations are priced and approved
- Acceptance criteria and handover documents
- Roles of the owner, designer and contractor
See Penthouse Design Group services and our pricing guide for starting questions when defining your scope.
An example from a real project
Grand Bangkok Boulevard 49 covers 590 sq.m. and includes both 3D visuals and completed-work photographs. It offers a way to examine how design-stage details reach the finished space. Assess the design thinking of a provider, deliverables and completed projects, not just 3D images or the total price.
FAQ
Does Design Only include construction supervision?
Do not assume this from the service name. Each company sets its own scope. Check the proposal for contractor-query support, material reviews, site meetings or construction management, including the number of visits and level of involvement.
Does Turnkey include everything?
Not necessarily. Read Turnkey together with the contractual inclusions, exclusions and definition of ready to use. Equipment, furniture, services or administrative costs may be separate.
Is appointing the designer and contractor separately cheaper?
The delivery model alone cannot answer this. The total depends on scope, specifications, quantities, site conditions and coordination costs. Compare the same information and scope.
How should I compare several contractor quotations?
Give each bidder the same drawings, specifications and BOQ. Clearly separate clarifications and exclusions so that quotations can be compared fairly.
Choose the Right Service for Your Project
At Penthouse, you can commission Design Only, including selected zones where the package fits, without appointing us for construction. Our construction service is available only for Penthouse-designed projects. Built-in work forms part of an appropriate project scope; we do not offer standalone cabinet production. See the latest packages on our Prices page
If you are unsure whether Design Only or an approach including construction is right for you, send your floor plan, budget range, preferred timing and desired level of involvement through our Contact page. Our team can help define the scope and the questions to resolve before choosing a delivery approach. We welcome conversations with clients comparing design teams; we do not take construction-only quotation requests for price comparisons.
Prepared by Penthouse Design Group — Interior design and construction team
