Best in class and quality when it comes to garage conversions, property renovation, and home extensions for Hertfordshire.

Stag Builders of Hertfordshire Limited is a family-run building firm, providing high-quality workmanship from skilled builders within the Hertfordshire region. We have always been proud of our work and keen when it comes to house extensions or renovating properties.

We cover all aspects of specialist building services such as kitchen installations, kitchen extensions, garage conversions, bathrooms, roofing, patios, house renovation, and what we do best home extensions. Property extensions is a large part of our bread and butter, and what we really enjoy.

Our Skilled building services and customer satisfaction is well known throughout the county of Hertfordshire, thanks to the highly skilled home builders we employ. We firmly believe that being a family-run business is central to our success.

Home Extensions Specialist Hertfordshire
House Extensions Hertfordshire

Specialist in garage conversions and garden rooms.

Property extensions and garage conversions for Hertfordshire : We offer a wide range of building services and are happy to advise if required. We can deal with planning permission submission, and architects drawings, should you need help with this part of your building project. 

We also advise our customers that sometimes it's a good idea to carry out a garage conversion, or garden room, in tandem with a remodel of your existing ground floor. This will allow you to rethink your whole floor plan ensuring you really maximise both spaces, as well as the way natural light will flow throughout the new space. 

Not only does a garage conversion or garden room allow you to make much better use of existing square footage without the need to extend. But it is also a project that creates minimum disruption to your living conditions whilst work is underway.

Another benefit of a garage conversion or garden room, especially in the Hertfordshire Region. Is that in the majority of cases you can convert your garage using permitted development rights. However, it is important that you check with the local Hertfordshire authority before starting work as these may have been removed or restricted.

Normally, except for conservation areas, the maximum area to be covered by garden buildings that are positioned more than 20m from any wall of the house is limited to 10m2. You can still have a garden building larger than 10m 2 in your garden if you wish you would just need to obtain planning permission before you can do so, and we can help with that.

Garden Rooms - Summer Rooms

Garden Rooms and Garage Convertions Hertfordshire

From handy home offices to guesthouses, even movie theatres, the possibilities are endless when converting a garage or extending your property with a garden room.

Garage Conversions

Extension Garden Room Hertfordshire

A garden room or garage conversion is one of the speediest and most affordable routes to adding floor space.

Residential building services

  • Plaster Board and Plastering

  • Exterior Wall Rendering / Repair

  • Garage Conversion

  • Loft Conversion

  • Renovation

  • Carpentry

  • Patio and Decking

  • Kitchens

  • Property Extensions

  • And many other services  See more >>

Why our skilled builders...

  • All our work is guaranteed

  • First Class Aftercare Service

  • We enjoy what we do

  • Our quotations are fixed price

  • Hertfordshire Based

  • St Albans

  • Harpenden

  • Watford

  • Radlett

  • Hertford

Rear Property Extensions

Garden Room - Hertfordshire

Garden Room

Architecturally beautiful and finished in natural materials. A garden room is premium, insulated for use all year-round. Allowing you to make the most of your new added space even in the colder winter months.

Loft Conversions

Loft Conversion Hertfordshire

Plastering & Loft Conversions

A large and spacious loft conversion in Harpenden, Hertfordshire. This loft space also featured a newly fitted en-suite bathroom. More on plastering.

We hope that the photos and information on our website, give you an idea of what we do. If you would like to obtain a fixed price quotation. Please contact us via the  Contact Form,  or call the nearest telephone number nearest to your location. 


By booking an appointment for us to visit your property. We will get more of an understanding of what is required. Helping us to generate a fixed price quotation, enabling you to budget safely.


At Stag Builders of Hertfordshire Limited, we make sure our terms of service are made clear, and our fixed price quotations guaranteed. 

Latest News...

As a result of the Covid-19 pandemic. We have seen a new property trend emerge.

We have seen an increase in enquiries from people wanting additional rooms, or dedicated areas that can work as a permanent home office space. Daily we have seen higher than usual call volumes, for planning applications to extend properties.


A real popular choice for many throughout the Hertfordshire region, has been to convert their garage into to a small office.