- Planning authority
- Welwyn Hatfield Borough Council
- Postcodes
- AL9, AL10
- Noon sun, 21 March
- About 38°
- Shadow from a 5 m eaves line
- About 6.3 m
- Planning plan
- Local Plan
- County
- Hertfordshire
What shapes a plot in Hatfield
Welwyn Hatfield Borough Council will judge a family home against the council’s Local Plan and any guidance it has adopted on garden development and annexes. Some councils spell out how closely an annexe must relate to the main house, such as sharing the drive, garden or parking, and what turns a building into a separate home instead. We read the current policies for your address before design starts, because a scheme drawn to suit the wrong test wastes time and money. Where the position is unclear, the council’s pre-application advice can be worth its fee.
The next steps, locally
Here’s what happens next for a family home in Hatfield. You tell us about your plot and who the home is for, and we carry out a free desktop appraisal of access, space and the planning context. If it looks viable we visit, then set out the annexe and separate-home options. With your go-ahead we survey, design and give you a written quote, then prepare the application for Welwyn Hatfield Borough Council.
Free plot appraisal
We look at your plot, access and the planning picture from the desk, talk through who will live in the new home, and visit if it looks viable. There’s no cost and no obligation.
Annexe or separate home
We set out both routes for your plot, covering what each means for planning, ownership, council tax, CIL and VAT, so you can decide with your family and advisers before design starts.
Planning and approvals
We prepare and submit the planning application and manage it with the council, which makes the decision. Before work starts, approval under the Building Regulations is in place and any CIL exemption has been claimed.
Build and handover
We build while you carry on living next door, with access, deliveries and working hours agreed up front. At handover you get the completion certificate and the paperwork you’ll need for council tax, lenders and any VAT claim.
Worth checking early
- Planning is the council’s decision, and an annexe is not a way round the rules that apply to a new house.
- CIL exemptions are lost if work starts before the claim is made, and can be withdrawn if the home is sold or let within three years.
- Family plans change: agree ownership, costs and what happens if circumstances change in writing, with a solicitor.
Hatfield: questions to ask
Will an annexe in Hatfield put up my council tax?
It might. Annexes can be banded separately, but exemptions exist for annexes lived in by certain dependent relatives, and in some cases a discount applies where family live there or the annexe is used as part of the main home. Who qualifies depends on the relative’s circumstances and how the annexe is used. Welwyn Hatfield Borough Council’s council tax team can tell you how the rules apply to your household.
Do I need planning permission for a granny annexe in Hatfield?
Yes, almost always for a detached annexe with its own kitchen, bathroom and bedroom. Welwyn Hatfield Borough Council will treat it as accommodation linked to your home and will usually add a condition so it can’t be let or sold separately. A garden building used only as a home office or gym is a different matter, but sleeping and cooking take it beyond those allowances.
Can I build a separate house in my Hatfield garden for my son or daughter?
Possibly, if the plot can work as a home in its own right. Welwyn Hatfield Borough Council will look at access, parking, garden space for both houses, privacy and the character of the street, as it would for any new house. If permission is granted, the plot can be transferred to your child with its own title, with your lender’s consent if the house is mortgaged.
How much garden do I need for a family home in Hatfield?
There’s no fixed figure. A single-storey annexe close to the house can work on a smaller plot than a separate dwelling, which needs its own garden, parking and access. What matters is whether Welwyn Hatfield Borough Council can be satisfied on privacy, daylight and the space left for both homes. The free appraisal gives you a first view based on your plot’s actual shape and access.
Other options in Hatfield
- Sell part of your garden
- Combine gardens with your neighbours
- Tandem and landlocked plots
- Planning promotion for your garden plot
- Bungalows on large plots
- Joint venture on your garden plot

