Granny Annexe Builders in Harrow, London
Suburban borough famous for Harrow School, with excellent schools and family-friendly areas. Grannexe has been helping families in Harrow and across London build beautiful, high-quality granny annexes for over 50 years. Whether you need accommodation for elderly parents, adult children, or a home office, we deliver turnkey solutions built to last.
Why Choose Grannexe in Harrow?
Based in Biggin Hill, Kent, we're your local granny annexe specialists serving Harrow and the surrounding London area. Unlike national companies, we offer a personal service from our family-run team who understand the local area, planning requirements, and building conditions.
50+ Years Experience
Family business building quality annexes since the 1970s. We've completed hundreds of projects across London.
Local to Harrow
We know London's planning requirements, soil conditions, and building regulations inside out.
10-Year Guarantee
Every annexe comes with our comprehensive 10-year structural guarantee for complete peace of mind.
Turnkey Service
From planning permission to keys in the door, we handle everything so you don't have to.
Granny Annexe Options for Harrow
Choose from our range of designs, all featuring our advanced WarmWall insulation system for year-round comfort and low energy bills.
Studio Annexe
Compact open-plan living with kitchenette, bathroom, and sleeping area. Perfect for single occupancy or couples who prefer simplicity.
- Open-plan living space
- Fully fitted kitchenette
- Accessible bathroom
From £90,000
View Studio Details
One Bedroom Annexe
Separate bedroom, living room, fitted kitchen, and bathroom. The most popular choice for couples and those wanting more space.
- Separate bedroom
- Spacious living room
- Full fitted kitchen
From £110,000
View One Bedroom Details
Two Bedroom Annexe
Two bedrooms, living room, kitchen, and bathroom. Ideal for couples wanting a guest room or home office space.
- Two bedrooms
- Large living area
- Optional second bathroom
From £130,000
View Two Bedroom DetailsAll prices include full turnkey completion with kitchen, bathroom, flooring, and decoration. Bespoke designs available on request.
Our Build Process in Harrow
From initial consultation to handing over the keys, here's what to expect when you build with Grannexe.
Free Site Survey
We visit your Harrow property to assess the site, discuss your requirements, and explain the options. This includes checking access, services, and any potential planning considerations. No obligation.
Design & Planning
We create detailed plans for your annexe, tailored to your site and requirements. We handle all planning applications or Permitted Development documentation, liaising with London council on your behalf.
Construction
Our experienced team builds your annexe using our advanced WarmWall construction system. Typical build time is 8-12 weeks depending on size and specification. We keep disruption to a minimum.
Completion & Handover
Your completed annexe is handed over fully finished with kitchen, bathroom, flooring, and decoration. We walk you through everything and provide all certification, warranties, and aftercare information.
Trusted by Families Across London
We've helped hundreds of families create the perfect living space for their loved ones.
"From start to finish, Grannexe were professional, communicative, and delivered exactly what they promised. Mum's new annexe is beautiful and she loves being close to us while having her own space. The quality of the build is excellent and the whole process was stress-free."— A satisfied customer from London
Ready to Build Your Granny Annexe in Harrow?
Get in touch today for a free, no-obligation site survey and quote. We'll visit your Harrow property and discuss the best options for your family.