Trusted Builders & General Contractors in Dulwich, Greenwich, Blackheath

JT Allen delivers exceptional building services across South East London. With over 35 years of experience, we’re the local building company homeowners trust for loft conversions, house extensions, kitchens, bathrooms, and complete renovations.

Why Choose JT Allen

35+ Years Experience — Established builders serving South East London
Fully Insured — £2M Public Liability & £5M Employers Liability
Family-Owned — Local, reliable, invested in our community
5-Star Rated — Proven track record of satisfied customers
Comprehensive Guarantees — 10-year structural, 5-year kitchen/bathroom
All Regulations Handled — We manage planning and building control

What We Offer

We deliver bespoke loft conversions, home extensions, and full renovations, tailored to your home. Quality workmanship, managed from start to finish.

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JT Allen – Your Local Building Firm

Looking for reliable builders near you? JT Allen is a trusted general contractor and building firm based in South East London, delivering professional construction services across Dulwich, Greenwich, Blackheath and surrounding areas.

We specialise in transforming homes through expertly designed loft conversions, seamless house extensions, and high-quality kitchen and bathroom renovations. As experienced building contractors, we handle projects of all sizes — from single-room refurbishments to complete property transformations.

When South East London homeowners search for a “builder near me” or “general contractor near me,” they’re looking for someone local they can trust. As an established construction company, we understand local architecture, planning requirements, and what our customers need.

Our Services

Loft Conversions

Transform unused attic space into beautiful living areas

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House Extensions

Rear, side, and wraparound extensions

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Building Works

Full renovations and structural alterations

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Kitchens

Complete kitchen design and installation

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Bathrooms

Bathroom fitting, en-suites, and wet rooms

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Carpentry

Bespoke joinery and fitted furniture

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Areas We Serve

We proudly serve homeowners throughout South East London:

Client Testimonials

JT Allen transformed our Victorian terrace in East Dulwich with a stunning rear dormer loft conversion. The attention to detail was exceptional, and they handled all the conservation area paperwork seamlessly. Highly recommended!

We chose JT Allen for our two-storey extension in West Greenwich after seeing their work on a neighbour's property. The quality exceeded our expectations, and they completed the project on time despite some challenging weather. True professionals.

Our Credentials

Get Your Free Quote Today

Ready to start your project? Contact JT Allen for a free, no-obligation consultation.