Everything You Should Know About Porch Foundations
Weâre proud to supply customers across the UK with the kits they need to build their ideal back and front porch designs. With years of experience in their manufacture, weâve also gained the knowledge we need to advise homeowners on porch foundations, why they need them, material foundation options, and depth measurements.
Read on to learn more about foundations before you start building a porch on your property, or call us or send us an email if you already know what you need to improve your home just as youâve been imagining.
Does a Porch Need Foundations?
A fully sized porch, complete with brick dwarf walls, columns, windows, and doors, will need foundations in order to comply with UK building regulations. Youâll be able to decide on everything else during the design and construction of your porch, but this part of the structure has to be included if you want to avoid having to change your plans. You may even end up having to remove the installation entirely, which would cost you both time and money that youâd spent putting it in in the first place.
We should note that you may also need building regulations approval for a porch if the structure is not separated from the rest of the house by an internal door and is heated, or if there are accessibility, drainage, or structural implications. If youâd like to know more about any of these, please get in touch with your local authority. Theyâll be able to provide you with more specific information for your area.


Can You Design and Build a Porch Without Foundations?
There are some porch types that can be built without foundations. These arenât fully enclosed and wouldnât be considered fully sized porches in comparison to full height and fully enclosed styles. Weâre more than capable of manufacturing timber frame kits for you to build your own porch without foundations in different styles:
These designs are manufactured from the finest green oak or Douglas-fir timber we have available, using a series of traditional jointing techniques so that each part of the frame will slot neatly together. As a result, if you have some previous DIY experience you should find that our products offer a quick, easy build with long lasting results.
With our service, you could soon fit your home with a back or front porch without foundations.
Why Does a Porch Need Foundations?
Porch foundations need to be in place because they form a steady, unmoving platform that prevents the walls and floors from separating. They support the structure once itâs built, and they also create a damp-proof barrier that helps to protect your property against potential damage from moisture or groundwater penetration. The concrete footing used during construction also adds an extra layer of insulation, helping to keep a property warmer for longer.
How Deep Should Foundations be for a Porch?
In most cases, building a porch onto your property will be a similar project to building a fully-sized extension. Itâs also likely that you wonât know how deep the foundations need to be until the ground where it will sit has been excavated and inspected for any âmade upâ areas (where the earth has been placed on the existing ground).
Itâs a good idea to excavate a trench through this earth layer into load-bearing ground, as this ensures that your foundation will have a strong base. Normally, trench foundations will be between 600mm wide and 450mm deep, though this depth can increase to as much as 1000mm. This will often depend on outside factors, such as the presence of tree roots, drains, or any other below-ground services that youâll need to take into consideration.
Building Control will also need to be involved, and you will need to provide a speculation for them to approve.
Porch Foundation Options
Material foundation options for porches in the UK are limited in order to keep to building regulations. Alongside the poured concrete block that will sit in the trench and help to form the footing, you will also need:
- A damp-proof membrane
- Plastic sheeting
- Polystyrene boards for insulation
Will the Porch Still Need Planning Permission?
You should find that most porches wonât need planning permission before you get started on your building project. This is because they fall under the terms of permitted development. However, there are some cases where you may have to make an application before you can go ahead with your project. These include:
- If the ground floor area (when measured externally) exceeds three square metres
- If any part is more than three metres above ground level (this should be measured the same way youâd measure a house extension)
- If any part of the porch is within two metres of any property boundary and the highway
To learn more about this, please see our advice on planning permission and porches.
Find Your Ideal Porch Design Here
If youâre planning on building a porch for your home, with or without foundations, get in touch with The Porch Specialist today. Weâll be fully prepared to provide everything you need to put your plans together, taking all specifications into account when we make the kit youâll use to build your own home improvement feature.
Youâll be able to get started on your construction project as soon as the work has been signed off and delivered (we deliver anywhere in the UK), and youâll even get to complete it on your own schedule to a budget-friendly price that youâve previously agreed with us.
Contact us today and weâll talk through your specifications for any back or front porch you have planned for your property, before our carpenters get to work building you the high quality kit that will make it a reality.