Barn Conversions in Hertfordshire and the Home Counties
Federation of Master Builders
30+ Years · 100+ Projects
Hertfordshire and Home Counties
Master Builder of the Year
Barn Conversions With the Character Kept In
A barn conversion is unlike any other project. The frame, the volume and the honesty of the original structure give you a home that simply cannot be built from scratch: vaulted ceilings, exposed timber, and light on a scale most houses never see.
It is also a project where experience matters. Structural condition, services, access and consent all need assessing properly before anyone falls in love with a drawing. At Mosaic Bespoke we survey first, advise honestly, and design conversions that keep the character while quietly adding modern comfort, insulation and performance.
Costs, timing and planning, answered up front.
What It Costs
As a guide, barn conversions typically cost between £1,800 and £3,000 per square metre, driven mainly by the condition of the structure and the level of finish. Some conversions also qualify for a reduced rate of VAT, which we will advise on.
Planning and Class Q
Many agricultural barns can convert under Class Q permitted development, without a full planning application. Listed buildings and those in protected settings need consent. We assess the route and manage the process for you.
How Long It Takes
Feasibility, design and consent typically take 3 to 6 months, with the conversion itself usually 6 to 12 months on site depending on scale and structure. You get a clear programme before you commit.
Why Convert a Barn?
Character that cannot be built new: original frames, dramatic volumes and a setting most plots will never offer. Done well, a conversion becomes the most distinctive home in the area.
Hertfordshire and the surrounding counties still hold a quiet supply of convertible agricultural buildings, and Class Q permitted development can unlock many of them without a full planning battle.
For owners and buyers alike, a properly converted barn holds its value exceptionally well, precisely because no two are the same.
Our Process.
Every project follows the same four-stage process, structured to provide clarity, manage planning risk, and ensure your conversion is comprehensively prepared before construction begins.
01
Discover
Opinion of Probable Cost
02
Define
Feasibility Study
03
Prepare
Pre-Construction Agreement
04
Deliver
Construction and Delivery
See what your barn conversion could cost
What type of extension are you planning?
Choose the option closest to your project.
Answer a few quick questions for an instant guide figure. The estimate is based on typical local build costs; for a detailed figure we will arrange a free consultation.
View our recent Extension Case Studies
Frequently Asked Questions
What is Class Q permitted development?
Class Q allows certain agricultural buildings to be converted to homes without a full planning application, subject to conditions on the building and its setting. We assess whether your barn qualifies and manage the approval process.
Can every barn be converted?
No, and it is better to know early. Structural condition, location, protected status and access all matter. We survey and give you an honest feasibility view before any design work begins.
How much does a barn conversion cost?
As a guide, between £1,800 and £3,000 per square metre depending on the structure and specification. The calculator above gives you a starting figure, and a survey firms it up.
Do you keep the original features?
Wherever we can, yes. Exposed frames, vaulted volumes and original openings are what make a conversion special. We design around the character rather than against it.
Is VAT reduced on barn conversions?
Qualifying residential conversions can attract a reduced rate of VAT rather than the standard rate, which can make a meaningful difference to the budget. We will advise on what applies to your project.
Considering a Barn Conversion?
Whether you own a barn or are weighing up buying one to convert, our appraisal gives you an honest view of feasibility, planning and cost before you commit.
Barn conversions across Hertfordshire and the Home Counties
We build barn conversions from our base in St Albans and across Harpenden, Radlett, Potters Bar, Hemel Hempstead and Berkhamsted, and throughout Hertfordshire, Essex and the southern counties. Exploring your options? See our house extensions page, or compare with loft conversions, basement conversions and double storey extensions.













































