For occupiers, landlords and developers
Best Design and Build Contractors London: How to Choose
Sviatoslav JerdetchiiCEO & Founder of Craftex. Updated , 5 min read
The short answer
The best design and build contractor has designed and built schemes like yours, takes real responsibility for the design and prices it openly before you commit.
- Ask who draws your scheme and whether they are employees.
- Check the contract says who carries the design risk.
- Ask how early the contractor comes in, and what that saved.
- Ask what share of the site labour is its own.
Design and build sounds simple: one contract, one price, one company responsible. In practice it depends on the contractor. Some have their own designers and site teams. Others pass the design to a consultant and the build to subcontractors, and sit in the middle. Both call it design and build.
This guide shows how to tell design and build contractors in London apart. It covers the routes, seven checks and how the types compare. We are a design and build contractor ourselves, and we say plainly where we are not the right choice.
Have a site or a brief? Book a site visit and we'll show you how we'd approach it.
First, be clear what you are buying
"Design and build" covers four different deals. Each one moves the design risk to a different place.
| Route | What it means | Suits |
|---|---|---|
| Full design and build | The contractor designs from your brief and builds it under one contract | Fit-outs, refurbishments and conversions where speed and one point of responsibility matter |
| Design and build with novation | Your architect takes the design to a stage, then transfers to the contractor | Schemes where you want to control the concept and planning first |
| Two-stage design and build | A pre-construction agreement first, then the build price once design is developed | Complex or unknown sites, basements, retained façades |
| Traditional | You appoint the designers; the contractor builds what they drew | Maximum design control, with the gaps between parties |
Our guides to design and build vs traditional procurement and the pre-construction services agreement explain each route.
Seven checks for design and build contractors in London
Each check is something you can test in the first two meetings.
1. In-house design, or design bought in?
Ask who will draw your scheme and whether they are employees. A contractor with designers in the same company can price as it draws. That is the whole point of the route.
2. Who carries the design risk, in writing?
Read the contract's design responsibility clauses. Check the contractor's professional indemnity insurance. If the price assumes things the design doesn't show, that should be the contractor's problem, not yours.
3. How early does it get involved?
The biggest savings happen at concept and feasibility, not on site. Ask when the contractor usually comes in. Ask what changed on its last project because it did.
4. Whose people do the work?
Ask what share of the site labour is directly employed. Around 60% of our labour is in-house. That keeps quality and pace under the same control as the design.
5. A record at your scale and type
A fit-out specialist is not automatically a residential developer. The reverse is just as true. Ask for finished schemes, not consented ones.
6. Planning and development judgement
On development work, design and build starts before planning. Ask who on the team has taken schemes through planning and on to sale or letting.
7. Price you can see into
A lump sum gives certainty, but you should still know what it includes. Ask whether a detailed cost plan, priced unit by unit, is available.
How the main types of design and build contractor compare
These are typical patterns, not verdicts on any firm.
| Type | Sweet spot | Watch for |
|---|---|---|
| National main contractor | Large, complex schemes | Design mostly by appointed consultants; small jobs get less attention |
| Regional or mid-size contractor | Mid-size new build and refurbishment | Mixed in-house design |
| Local general builder | Small works | Rarely designs |
| Design-led studio that also builds | Design-led interiors | Build often subcontracted |
| Developer-contractor | Appraisal, design, planning and build in one team | Check its record on your building type |
Why a developer's view matters on design and build
Most design and build contractors think like builders: scope, cost and time. A developer also needs to know what the finished scheme is worth. How will planning treat it? How fast will it sell or let? That is why our Development Director sits in the same team as our designers and site managers.
Rob Barton spent over 20 years in managing director and land director roles at plc housebuilders. There he delivered more than 4,000 homes and acquired over £225M of land. These were his previous roles, not Craftex projects.
In a design and build appointment, that means the scheme is tested against value and planning before it is drawn in detail. Depending on the stage, Craftex can co-invest, take 100% of the risk, or work on a percentage or fee basis.
The rest of the team, again with earlier projects from previous careers:
- Joe Crawford, Operations Director: 37 years, on projects from £100K to £135M, including Dior's flagship on Bond Street.
- Martin Hickey, Preconstruction Director: more than 50 years, leading preconstruction and project management.
- Konstantin Jegorovs, Projects Director: 16 years in retail and commercial, on flagships of up to £5 million.
I worked perfectly with Sviat and Joe, with their architect they came up with a very smart design for our office to fit more desks and optimise the space to its maximum capacity. They also did excellent value engineering on the MEP design proposed by others, allowing us to save around £50K. The quality and speed were outstanding we finished two weeks ahead of schedule. Highly recommend these guys.
Design and build at work
Three projects show what one team for design and build changes.
Medusa: a concept brought into budget
The client came to us at RIBA Stage 2, with a concept, some 3D visuals and a budget. Because our designers and builders sit together, we could see what the concept would cost. We adapted it to fit the budget. Medusa is 180 sq m over four floors, designed and built in 17 weeks.
Portsoken House: accurate pricing on a conversion
At Portsoken House an empty warehouse became 1,550 sq m of offices. We designed it in-house and built it in seven months around occupied floors. Keeping design and build under one roof gave the client accurate pricing and real savings. The project value was £2.2M.
Drake's: a design shaped by the building
Nothing could be fixed to the railway arch at Drake's warehouse. So we designed a self-supported interior: freestanding partitions and independent service frames. It covered 500 sq m in eight weeks, for £200K.
Outside London, Craftex took part in Leicester One, a £3.9M, 56-room student residence. Every project we have delivered has finished ahead of programme and on budget.
Where Craftex is not the right fit
- Very large new builds that need a national contractor's balance sheet. If your funder expects a top-tier contractor, appoint one.
- Small works. Below about £100,000, a full design and build process rarely pays back.
- You want to own every design decision. If your own architect must keep full control, a traditional route is more honest.
See how our design and build and turnkey contracting process runs. If you're comparing design and build contractors in London now, book a site visit and test us against these checks.
