Frequently Asked Questions

Many house extensions in Devon fall under Permitted Development rights, depending on property type, size and whether your home is in a conservation area or Area of Outstanding Natural Beauty. However, local authority interpretation can vary. We can review your property and advise whether planning permission or a Lawful Development Certificate is required.

A Lawful Development Certificate provides formal confirmation from your Devon local authority that your extension complies with Permitted Development rules. While not always mandatory, it is strongly recommended to protect resale value and avoid future legal uncertainty.

For most extensions in Devon, we recommend Full Plans approval. This allows building control to review drawings before work begins, reducing construction-stage risk such as cost or delay. Building Notice can be suitable for smaller or simpler projects but carries more uncertainty.

We're experienced enough to make robust assessments across Devon and Somerset, so are happy to visit properties in Tiverton, Exeter, Cullompton, Taunton and the surrounding areas to provide a full quotation based on the likely design/planning permission. We'll always be clear about what elements of this quote are subject to external design.

Yes. We coordinate with either local authority building control or approved inspectors in Devon to ensure your extension meets all current Building Regulations requirements.

Extension costs in Devon vary depending on size, access, specification and ground conditions. As a general guide, single-storey extensions in Devon typically range from £2,200–£3,000+ per m². More complex designs or high-spec finishes may exceed this range. We provide clear, itemised quotations so you understand exactly what is included. For a personalised estimate for your extension project in Tiverton, Exeter, Cullompton, Taunton or elsewhere in Devon, contact us for a free, no-obligation quotation.

Most single-storey extensions in Devon take approximately 8–14 weeks on site, depending on size and complexity. Planning and building control approval should be factored in before construction begins, to avoid delays during construction.

Ground conditions in Devon vary significantly, particularly in rural areas where clay, shale or made ground may be present. Foundation depth and design can vary as a result, which can lead to higher costs, but not always. Radon, a naturally occurring gas, is also common, which requires some additional detailing to protect the homeowner. In Devon we are also living in a severe or very severe exposure area in relation to wind-driven rain, which may lead to additional detailing such as check reveal or partial fill insulation to ensure no damp penetrates through to habitable areas. As a result, although costs are not always higher in Devon, the above can lead to higher costs.

Most extensions in Devon require structural calculations for steel beams (RSJs), roof spans or load-bearing wall removals. This can be managed by ourselves through the design process.

Most Devon homeowners remain in their property during construction. We carefully plan structural openings and service alterations to minimise disruption.

The first step is an initial conversation about your property, budget and goals. Whether you're based in Tiverton, Exeter, Cullompton, Taunton or anywhere across Devon and Somerset, we can advise on planning, structural requirements and next steps. We can complete as a full turnkey solution with design, structural calculations, building control notices through to final decoration and handover. Contact us here.