Frequently Asked Questions

Our projects typically range from £60,000 for a well-specified extension to over £2M for bespoke new builds and heritage conversions. We focus on quality-driven projects where craftsmanship and attention to detail are priorities. If your project is below £60,000, we're happy to recommend trusted colleagues who may be a better fit.

It depends on the scope. Many rear extensions fall under permitted development rights, while new builds, heritage works and conversions almost always require planning. We manage the entire planning process — from pre-application advice through to discharge of conditions — and have a strong track record of approvals across Essex and the South East.

Transparency is central to how we work. Every project begins with a detailed specification and fixed-price quotation. We use a milestone-based payment schedule, provide monthly cost reports and flag any potential variations before they become commitments. Over the past five years, 94% of our projects have completed within 3% of the original quotation.

Absolutely — and we often do. We collaborate regularly with architectural practices across the South East, from small residential studios to larger firms like Michaelis Boyd and Proctor & Matthews. If you don't yet have an architect, we can introduce you to practices whose style and expertise match your project.

All structural work carries a 10-year Hartwell & Stone guarantee, underwritten by our FMB membership. New builds are additionally covered by NHBC Buildmark warranty. Heritage works are guaranteed for materials and workmanship for 10 years. We also provide full Building Regulations sign-off and completion certificates on every project.

We're based in Chelmsford and work extensively across Essex, East London, the Home Counties and East Anglia. For larger projects — typically new builds and heritage conversions above £500,000 — we work nationwide by arrangement. Our current furthest project is a barn conversion in the Cotswolds.

Timescales vary by complexity. A well-specified extension typically takes 4–6 months from start on site. Whole-house renovations run 6–10 months. New builds and heritage conversions are typically 12–18 months. We provide a detailed programme at quotation stage and update it fortnightly throughout the build.

Heritage work is one of our specialisms. We have a dedicated heritage team experienced in lime mortars, traditional joinery, sash window restoration and conservation-grade materials. We work closely with conservation officers and, where required, Historic England. Our recent LABC Building Excellence Award was for a Grade II listed Georgian restoration in Chelmsford.