What a garden annexe is for
- Guests or family who come to stay
- An older parent living close by
- A teenager who wants their own space
- A bedroom with a shower room and kitchenette
Garden annexes near me in Hemel Hempstead HP1
Looking for garden annexes near Hemel Hempstead HP1? This page is for homeowners in Hemel Hempstead, Hertfordshire. You describe the room you want, and we match you with builders who already take on work in and around Hemel Hempstead, so nobody has to drive across the county to see your garden.
Garden Room Match is a matching service, not a builder. Up to 3 local builders get your request, each visits your Hemel Hempstead plot for free, and each sends a written quote you can compare like for like.
A garden annexe in Hemel Hempstead is a popular project because a bedroom with a shower room and kitchenette. Every request is read by a person on our side before it goes to builders, so a postcode in HP1 that is outside a builder's range does not get passed on by mistake.
Local garden annexe builders in Hemel Hempstead
The builders we work with already take on garden annexes in Hemel Hempstead and the area around it. That matters because a builder who knows Hertfordshire knows how Dacorum Borough Council handles outbuildings, which ground is clay or chalk, and which roads are awkward for a delivery lorry.
Every builder we work with is insured and established: public liability cover and three or more years trading. They give written quotes, so you compare the same things across 3 quotes instead of three different conversations. There is no fee to you; builders pay for introductions. We cannot promise a particular builder will be free on your dates, which is why you get up to 3 to choose from.
How it works in Hemel Hempstead: three steps
- 1
Tell us about your garden
Answer a few questions: the room you want (garden annexe), roughly how big, and your HP1 postcode. It takes about a minute and costs nothing.
- 2
Up to 3 Hemel Hempstead builders visit
We pass your request to up to 3 builders who work near Hemel Hempstead. Each visits for free, measures the plot, checks access and asks what you want from the room.
- 3
Compare written quotes
You get written quotes to compare like for like. Pick one, ask questions, or walk away. Expect to hear back within 48 hours.
What a garden annexe costs in Hemel Hempstead: guide prices by size
These are guide prices, not quotes. They come from the same size bands as our garden room cost calculator and include VAT. A Hemel Hempstead builder who has seen your garden will give you a firmer figure in writing.
A room someone sleeps in needs building regulations sign-off and more heating. For a garden annexe the calculator adds £4,000 to £7,000 on top of the size price. Typical price: from £39,000, fitted, including VAT.
Guide figures for fitted rooms, including VAT. Not a quote: your written quotes depend on your plot. Prices assume easy access to the garden. If materials have to be carried through the house, the calculator adds £1,000 to £2,500.
| Size | Garden annexe guide price |
|---|---|
| SmallAbout 3 × 3 m | £16,500 to £25,000 |
| MediumAbout 4 × 3 m | £22,000 to £36,000 |
| Large5 × 4 m and up | £36,000 to £65,000 |
Guide figures including VAT, rounded to the nearest £500 as in the calculator. Not a quote.
What a garden annexe adds to the basic build
A room someone sleeps in is the biggest step up.
- Building regulations sign-off for sleeping space
- Shower room or WC with drainage to the main sewer
- Kitchenette, more heating and often planning permission
Common extras and what they add
| Extra | Adds (guide) |
|---|---|
| Reinforced floorFor racks and heavy kit | £1,500 to £3,000 |
| Sound insulationPlaying or recording | £1,000 to £2,500 |
| Shower room / WCNeeds drainage | £5,000 to £9,000 |
| KitchenetteSink, worktop, water | £2,500 to £5,000 |
| Air-conHeating and cooling | £1,500 to £3,000 |
| Extra glazing / roof lightsMore daylight | £1,500 to £4,000 |
| Long power / water runFar from the house | £1,000 to £3,000 |
| Through the houseMaterials carried in by hand | £1,000 to £2,500 |
Work out your own figure in the cost calculator · Garden room costs guide
What affects the price of a garden annexe on a Hemel Hempstead plot
Builders in Hemel Hempstead tell us the same thing every time: the building is only part of the price. The rest is ground, access and services, and those are different on every road in HP1.
Before you compare quotes, check that each one covers the same things from this list, cheapest to dearest: size and height, foundations: ground screws, pads or a slab, cladding and roof finish, amount and type of glazing, distance for power, water and drains and access: can materials reach the garden?. A quote that leaves one of these out is not the same job as one that includes it.
As a worked example, a medium garden annexe with shower room / wc and kitchenette comes to £29,500 to £50,000 in the calculator. Use the cost calculator to build your own combination.
Planning in Hemel Hempstead: check before you build
The national register lists 2 conservation areas within about 1.5 km of the centre: Hemel Hempstead Old Town and Piccotts End; on designated land such as a conservation area, an outbuilding at the side of a house needs planning permission. Green Belt land lies within about 1.5 km; Green Belt does not by itself remove outbuilding rights and matters only if an application is needed. No register entry within that distance removes the outbuilding right, but the register can be incomplete, so check your street with Dacorum Borough Council.
Planning applications in Hemel Hempstead go to Dacorum Borough Council. If you are unsure, ask the council or apply for a lawful development certificate, which confirms in writing that a design is permitted development.
What your builder checks for your plot
- The height of the room, and how near it is to your boundary
- How far it is from the house, and its floor area
- Whether your home is in a conservation area or listed
- Whether anyone will sleep in it, because building regulations then apply
General guidance, not legal advice. Check the rules on the Planning Portal and with Dacorum Borough Council.
Planning a garden annexe in Hemel Hempstead: points for this room
- Permitted development does not cover an outbuilding used as a bedroom, bathroom or kitchen. That is "primary living accommodation".
- So an annexe someone sleeps in usually needs a planning application. Check with your council.
- Councils often approve annexes on the basis that they stay linked to the main house, not a separate home. Check with your council.
- Sleeping space removes the building regulations exemptions, so building control sign-off is needed at any size.
- A shower room or WC needs drainage, and new circuits are notifiable under Part P.
Permitted development limits for a garden annexe in Hemel Hempstead
Most garden annexes in England do not need a planning application because they count as permitted development, but only inside a set of limits. These are the national limits for outbuildings. They apply to Hemel Hempstead homes as they do everywhere else in England, and your builder checks them against your plot before you commit.
- It must be single storey, with eaves no higher than 2.5 m.
- It can be up to 4 m high with a dual-pitched roof, or 3 m high with any other roof.
- If any part is within 2 m of a boundary, the whole building can be no higher than 2.5 m.
- Height is measured from the highest ground right next to the building.
- It must not sit forward of the front wall of the house (the principal elevation).
- All extensions and outbuildings together must cover no more than half the land around the original house.
- No verandas, balconies or raised platforms. A platform must be no higher than 0.3 m.
- The use must be "incidental" to the house. A bedroom, bathroom or kitchen does not count.
Where the limits are tighter near Hemel Hempstead
Some land has stricter rules than the national limits. In Hertfordshire the ones that come up most are listed below. Whether your address is inside one is something to confirm with Dacorum Borough Council.
Conservation areas
An outbuilding between the side wall of the house and the boundary needs planning permission.
National Landscapes (AONB)
The side-wall rule applies. Anything more than 20 m from the house is limited to 10 m² in total. The Chilterns National Landscape covers parts of both Hertfordshire and Buckinghamshire, so check whether your address is inside it.
Listed buildings
Any outbuilding within the grounds of a listed building needs planning permission.
Flats and maisonettes
These permitted development rights do not apply.
Article 4 directions and old conditions
A council can remove permitted development rights in an area, or a past planning condition can remove them for one house.
Building regulations for a garden annexe in Hemel Hempstead
Planning permission and building regulations are different things, and a garden annexe in Hemel Hempstead can need one, both or neither. For building regulations the question is floor area and sleeping space. The bands below apply across England, including Hertfordshire.
Under 15 m² floor area
Building regulations do not normally apply, as long as nobody sleeps in it.
15 m² to 30 m²
Building regulations do not normally apply, as long as nobody sleeps in it and it is either at least 1 m from every boundary or built mostly of non-combustible materials.
Over 30 m²
Outside these exemptions, so building regulations approval is normally needed.
Any size with sleeping space
The exemptions do not apply once a room has sleeping accommodation.
Electrics matter whatever the size. A new circuit to a garden annexe is notifiable under Part P, so use a registered electrician or ask your builder who certifies it. Building regulations guide
Other garden room types in Hemel Hempstead
Not sure a garden annexe is the right room? The same Hemel Hempstead plot can take any of these. Each page shows prices, planning and questions for Hemel Hempstead.
Garden offices in Hemel Hempstead
The simplest build: an insulated room with power, lights and heating. From £16,500, fitted, including VAT.
Read more →Garden gyms in Hemel Hempstead
Heavy kit and hard training need a stronger, cooler room. From £21,000, fitted, including VAT.
Read more →Garden studios in Hemel Hempstead
Light and sound decide the spec. From £18,500, fitted, including VAT.
Read more →All garden rooms in Hemel Hempstead
Villages and areas we cover near Hemel Hempstead
We match Hemel Hempstead homeowners with builders who work across Bovingdon, Leverstock Green, Berkhamsted, Kings Langley, Harpenden and St Albans. If your home is on the edge of Hemel Hempstead, or in a village outside it, the same page and the same form apply: use the HP1 postcode of your house.
Each nearby town has its own page with its own council and planning notes: Berkhamsted, Kings Langley, Harpenden and St Albans. Rules and councils differ even a few miles apart, so check the page for your own town too.
- Bovingdon
- Leverstock Green
- Berkhamsted
- Kings Langley
- Harpenden
- St Albans
Guides to read next
Garden room planning permission in Herts & Bucks
Do you need planning permission for a garden room? The permitted development limits for outbuildings in England, and where Herts & Bucks rules are tighter.
Read the guide →Garden room costs: how a price is built
How garden room prices are built: size, foundations, cladding, glazing, services and access, plus what offices, gyms, studios and annexes add.
Read the guide →Garden rooms in conservation areas and the Chilterns
How conservation areas, Article 4 directions and the Chilterns National Landscape change the garden room rules in Herts and Bucks.
Read the guide →Garden annexe rules: planning and building regs
Planning permission and building regulations for a garden annexe in England: incidental use, sleeping space, and what to ask your council.
Read the guide →
Garden annexes in Hemel Hempstead: questions people ask
Do I need planning permission for a garden annexe in Hemel Hempstead?
The national register lists 2 conservation areas within about 1.5 km of the centre: Hemel Hempstead Old Town and Piccotts End; on designated land such as a conservation area, an outbuilding at the side of a house needs planning permission. Green Belt land lies within about 1.5 km; Green Belt does not by itself remove outbuilding rights and matters only if an application is needed. No register entry within that distance removes the outbuilding right, but the register can be incomplete, so check your street with Dacorum Borough Council. Planning applications in Hemel Hempstead go to Dacorum Borough Council.
How much does a garden annexe cost in Hemel Hempstead?
Guide price for a fitted garden annexe: £16,500 to £25,000 for a small room, £22,000 to £36,000 for a medium room and £36,000 to £65,000 for a large one, including VAT. These are not quotes. Your written quotes from Hemel Hempstead builders show the real figure for your plot.
Does a garden annexe in Hemel Hempstead need building regulations?
Not normally under 15 m² if nobody sleeps in it. From 15 m² to 30 m² it is also normally exempt if it is at least 1 m from every boundary or built mostly of non-combustible materials. Over 30 m², or with any sleeping space, approval is normally needed. You can use the local authority building control service for your area or a registered building control approver.
How many garden annexe quotes will I get in Hemel Hempstead?
Up to 3 written quotes from builders who already work in Hemel Hempstead and nearby areas such as Berkhamsted, Kings Langley, Harpenden. Each one visits for free first. The service is free for homeowners.
Which council handles planning in Hemel Hempstead?
Dacorum Borough Council. Your builder checks the rules for your plot before you commit.
Do you cover villages near Hemel Hempstead?
Yes. We match homes across Bovingdon, Leverstock Green, Berkhamsted, Kings Langley, Harpenden and St Albans. Enter your postcode in the form and we confirm whether builders cover your address.
What does Garden Room Match cost me?
Nothing. The service is free for homeowners. Builders may pay us a fee for each introduction.
How long does a garden annexe take to build?
Most installs take 4 to 8 weeks once the design is agreed. Lead times change through the year.
