Hiring House Extension Specialists: Questions to Ask Before Work Begins

October 23, 2026

An extension can change the way you use your home every day. A cramped kitchen may become a proper family space, or an awkward layout may finally make sense once you have the extra room you need.

The construction work, though, can be disruptive. There will be decisions about the design, costs, access and how the existing house connects to the new structure.

Choosing the right house extension specialists can make those decisions easier to manage. Before signing a contract, make sure you understand what the builder will do, what the price includes and how the project will be handled if something unexpected happens.

1. Does the Builder Understand Your Type of Extension?

Not every extension presents the same challenges.

A single-storey addition may require a different approach from a two-storey extension or a project that involves substantial alterations to an existing roof. Site access and the condition of the house can also affect the work.

Ask about projects with similar requirements. Discuss the proposed layout and find out whether the builder sees any issues that need to be resolved before construction starts.

This is also the time to explain how you intend to use the new space. The design should work for your household rather than simply fit within the available footprint.

2. What Does the Quotation Include?

A quotation should provide enough detail for you to understand what you are paying for.

Check whether it includes groundwork, foundations, structural work, roofing, insulation, windows, services and internal finishes. Confirm which professional fees and approvals sit outside the building contract.

Ask how provisional sums and unforeseen work will be treated.

If one quotation is much lower than another, compare the scope before assuming it represents better value. The difference may reflect missing work or a different specification.

3. What Planning and Building Control Requirements Apply?

Some extensions may fall within permitted development rights, while others require planning permission. Building Regulations may apply regardless of whether planning permission is needed.

The requirements depend on the property, proposed design and applicable rules. Listed buildings, conservation areas and other restrictions can change what is possible.

Discuss the necessary checks early and confirm who is responsible for coordinating the relevant applications and inspections.

Do not assume that planning approval covers every technical requirement. Structural safety, insulation, ventilation, drainage and fire safety may all need consideration.

4. How Will the New Structure Connect to the Existing House?

The junction between an extension and the original building is one of the most important parts of the design.

Roof levels, foundations, drainage and the connection between the old and new walls need to be resolved. Insulation must also be detailed carefully to reduce thermal bridging and unwanted air leakage.

Ask how the builder intends to deal with these connections and whether structural or other specialist input is needed.

This is particularly important if the existing property has older construction or a history of damp.

5. Would Timber Frame Construction Suit the Project?

Timber framing can be a useful option for extensions where the design and site conditions suit the method.

It may allow parts of the structure to be prepared in advance and assembled efficiently. The wall system can also be designed to accommodate insulation and the required airtightness measures.

The complete specification still matters. Weather protection, moisture management and the connections between the extension and the original building need to be handled properly.

Kindred Construction's timber frame extension in Ottery St Mary is a relevant example. The project combined a timber structure with glulam trusses, triple glazing, wood fibre insulation and reclaimed materials.

Ask whether a similar approach would be suitable for your own property, rather than assuming the same system will work on every site.

6. How Will the Work Affect Daily Life?

If you intend to remain in the house during construction, discuss access, dust, noise, water and electricity interruptions before work begins.

Ask where materials will be stored and how workers will enter the site. If the kitchen or bathroom will be unavailable at any stage, establish how long that period is expected to last.

The builder should explain the likely sequence of work and keep you informed when changes affect the household.

Clear communication will not prevent every disruption, but it can make the process easier to manage.

7. Can the Project Improve the Existing Home's Energy Performance?

An extension is an opportunity to improve the building fabric, particularly if the project includes alterations to the original house.

Discuss insulation, glazing, airtightness and ventilation as part of the overall design. The new structure should meet the applicable requirements, and the junction with the existing property needs careful attention.

If the work includes older walls, get advice before adding insulation. Traditional buildings may need a different moisture-management approach from modern cavity-wall construction. Historic England's guidance explains why insulation and moisture risks need to be considered together in older properties.

8. What Happens When the Project Changes?

Unforeseen issues sometimes emerge after walls are opened or foundations are exposed.

Before work begins, agree how the builder will explain a problem, provide a revised price and obtain approval for additional work.

Avoid relying on informal verbal agreements for significant changes. Written confirmation makes it easier for everyone to understand the agreed scope and cost.

Choosing an Extension Builder in East Devon

A good extension project starts with a clear brief and realistic expectations. You should understand the quotation, the construction method and the responsibilities of everyone involved.

Kindred Construction works across East Devon, including Exeter, Exmouth, Honiton and Ottery St Mary, undertaking residential extensions, renovations and new builds.

Visit Kindred Construction to discuss your plans and explore a suitable approach for your home.

Thinking about extending your property? Start with a conversation about the space you need, the constraints of the site and the construction options worth considering.