How to choose a design and build company in London

London is a demanding place to renovate. Planning constraints, heritage rules, complex structures and close neighbours mean the firm you appoint matters more than the drawings you start with. This guide sets out how to compare design and build companies here, and what a full answer to each question sounds like.

What you are actually choosing between

Three routes compete for the same job.

• Architect led. An architect designs, a quantity surveyor prices, and a contractor is tendered separately. You hold the gaps between the three.
• Main contractor. You bring a finished design and the contractor builds it. Buildability problems surface late, as variations.
• Design and build. One firm carries the design, the cost plan and the construction under one contract. Fewer gaps, and one point of accountability.

None of the three is wrong. What matters is knowing which one you have bought, and who carries the risk inside it. Our note on the architect led and design and build routes compares them in more detail.

What separates firms at the top of this market

• Completed work of comparable scale, in comparable postcodes.
• Experience of structural refurbishment, basements and listed buildings.
• Cost planning held in house, so the price and the drawing move together.
• Programme control that survives an approval slipping.
• Discretion, because most work at this level is never published.
• Referrals and repeat clients rather than advertising.

Eight checks to run before you appoint

1. Ask to see three completed projects like yours

Not the three they show everybody. Three of the same type, scale and finish. Ask what the firm designed, what it built and what it managed on each one.

2. Ask who you will actually deal with

Get the name and the role of the person running the job. Ask how often they will be on site, and who covers when they are not.

3. Ask how the cost plan is built

Ask whether the quantity surveying is in house or bought in. Ask to see a cost plan split by element, with the provisional sums marked.

4. Ask what the programme assumes

A programme should start at survey and end at handover. Ask which dates depend on planning, building control, a freeholder or a party wall award.

5. Ask how a change is priced

Ask for the rule in writing before you sign. A change priced after the event is a change priced without competition.

6. Ask about the building services

Heating, cooling, ventilation, lighting control and data decide ceiling heights and joinery. Ask when they are coordinated, and by whom.

7. Ask what happens when something is found behind the plaster

Every old London house hides something. Ask how it is recorded, priced and agreed, and what the contingency is actually for.

8. Ask what aftercare looks like

Ask for the defects period, the certificates, the manuals, and the name of whoever answers the phone in month nine.

How NU Projects answers them

NU Projects has worked in West and prime central London since 2010, which is sixteen years. The work is mostly structural refurbishment, basements, listed property and whole house projects.

Architecture, interior design, quantity surveying, project management and construction sit inside one firm and one contract. Clients deal with senior people from feasibility through to handover, and the cost plan is built by the same team that builds the house.

Completed work is on the projects pages, the scope is set out under services, and the rates are published in the build cost calculator.

Reading the answers

Put the same eight questions to every firm on your list and write the answers down. The differences will not be in the adjectives. They will be in who carries the design responsibility, what is inside the price, and what happens when something changes.

Considering a design and build project in London?

To talk to the team, send two lines through the contact form. You can also call 020 7731 6841. We usually reply within a few hours, weekends included.