Before you ask for quotes, decide how you will run the project. There are two common routes for extensions and new homes: design and build, and architect plus separate builder. Each suits different people.
Design and build
One company is responsible for the design (often through in-house designers or partners) and the construction, under a single contract.
Advantages
- One point of contact and responsibility
- Design is shaped by what can be built and what it will cost
- Earlier price certainty and often a quicker start
- Fewer disputes about who is to blame for a problem
Disadvantages
- Less independent oversight of the builder
- Less choice if you want a particular architect's style
- You need to be comfortable with the single supplier
Best for: straightforward extensions, refurbishments and homeowners who want a simple process.
Architect (or designer) plus builder
You employ an architect or designer to produce the drawings and a separate builder to construct them, often after competitive tendering.
Advantages
- Independent design advice and a bespoke result
- The architect can inspect the work and administer the contract
- Competitive tenders may help you test the price
Disadvantages
- More coordination, more contracts and more people
- Risk of a design that is more expensive than your budget
- Delays if the builder needs to price and then redesign
Best for: complex, high-specification or heritage projects and clients who want a strong design.
Cost comparison
Neither route is automatically cheaper. Design and build can reduce design changes and give early cost advice. A separate architect adds fees (commonly a percentage of build cost or a fixed fee) but may result in a better-designed and more carefully specified project. Compare using our extension cost guide and by checking what each fee covers.
Other points to consider
- Planning and regulations: Either route should include planning and building regulations support. Confirm who is responsible.
- Contract: Be clear about who carries the risk if drawings are incomplete. See builder contracts and stage payments.
- Project management: On larger jobs, someone must coordinate trades; see do you need a project manager?
- Design process: Our dream home design guide walks through the steps.
How to choose
- Is your project simple or complex?
- How involved do you want to be?
- Do you need a specific architectural style?
- How certain is your budget?
- Do you already have drawings?
If you already have drawings, a builder can price them directly. If not, ask builders what design support they can offer.
Talk to Abron Contracting
If you have plans, we can price them. If you are at an earlier stage, we can discuss options and recommend next steps for residential construction in Newport and beyond. Contact us or call 01633379170.
Frequently asked questions
What is design and build?
A contract where one company handles both the design and the construction.
Is design and build cheaper?
Not always, but it can give cost certainty earlier and reduce changes later.
Do I need an architect for an extension?
Not always. Many extensions can be designed by an architectural designer or a design and build contractor, but complex projects benefit from an architect.
Who is responsible if the design is wrong?
It depends on the contract. Under design and build, usually the single provider. With separate appointments, responsibility is split, so be clear in writing.
Can I use drawings from another designer?
Yes. Builders can price existing drawings, but they must be detailed enough to quote accurately.
