Hertfordshire
Sue's Rear Extension & Bifold Doors
Full rear extension from foundations up. Matching brick, bifold doors, porcelain patio. Fully plastered, decorated, and ready to furnish on handover.
View Case Study Extensions
From single-storey kitchen extensions to full double-storey additions, MJD has built dozens of extensions across Hertfordshire and surrounding areas. We manage everything in-house — foundations, brickwork, roofing, windows, plastering, and decoration. You get one team, a fixed price, and a finished room that looks like it was always part of your home.
What to Expect
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Free Survey & Quote
We visit your property, listen to what you want to achieve, and provide a detailed written quote covering everything from groundworks to final decoration. No guesswork, no hidden extras — just a clear price before we start.
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Design & Planning
We'll advise whether your project falls under Permitted Development or needs a full planning application. If planning is required, we can manage the submission ourselves or work alongside your architect to keep the process moving.
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The Build
Our team manages every stage: foundations, structural work, brickwork, roofing, first and second fix, plastering, and decoration. You have one dedicated point of contact throughout and regular progress updates so there are no surprises.
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Handover & Snagging
We walk through the finished extension together, work through the snagging list, and hand over a clean, fully finished space ready to furnish. You'll also receive your building control completion certificate — essential for any future sale.
Projects We've Completed
Hertfordshire
Tracey's Extension
Rear extension adding a large open-plan space to a semi-detached property. Steel beam, vaulted ceiling, new French doors opening to garden.
View Case Study
Hertfordshire
Lucy's Extension
Side-return extension utilising redundant side access. Reconfigured the ground floor layout entirely to create a much larger kitchen-diner.
View Case Study"We'd wanted to extend for years but kept putting it off after hearing nightmare stories. MJD were completely different — they explained everything clearly, stuck to the price they quoted, and the build ran pretty much exactly to schedule. The bifolds were the finishing touch we'd always wanted. Couldn't be happier."
Extensions FAQs
- Do I need planning permission for an extension?
- Many extensions fall under Permitted Development rights, meaning no planning application is needed. As a guide, single-storey rear extensions up to 4m deep (detached house) or 3m (semi-detached or terraced) typically qualify — though there are conditions around width, height, and materials. We check your specific property before anything else. If planning is required, we'll advise on the best route and can manage the submission.
- How long does an extension take?
- A single-storey extension typically takes 12–16 weeks from start to handover. A double-storey is usually 18–24 weeks. These figures cover all trades but don't include any planning permission lead time (typically 8–10 weeks if needed). We'll produce a detailed programme when we quote so you know exactly what to expect.
- Can I stay in my home during the build?
- In most cases, yes. We work methodically to minimise disruption and your home remains habitable throughout. We'll be clear about which areas and services will be temporarily affected — especially if we need to break through into the existing house — so you can plan ahead.
- What's included in your quote?
- Everything needed to reach a fully plastered, decorated, and weathertight finish: all labour, materials, structural work, building regulations inspections, and the building control completion certificate. The only typical exclusions are furniture, kitchen appliances, and specialist items you've sourced independently.
Thinking about an extensions?
Let's talk.
We'll visit your property, listen to what you want to achieve, and give you a clear written quote. No pressure, no obligation.
Email: info@mjdbuilds.com