A knock through is the term that is used to describe removing an internal wall to connect two spaces or to incorporate a new kitchen extension, dining room or living room into an existing layout. In older properties removing interior walls is common practice during a home improvement or renovation project as this the only way to achieve open plan living. But before you start knocking down walls, you need to know what is involved.
A knock though is generally not the most complex part of a home improvement project, but it is still a good idea to consult a structural engineer before you start swinging the sledgehammer. You don’t want to damage or remove structural walls and have your whole house come tumbling down on top of you. When you embark on a renovation project, it is up to you to ensure the structural integrity of your property remains sound and that you retain any special architectural features and period character.
Consult a structural engineer
More often than not, a knock through is a simple part of a renovation project, especially if you are only removing non-loadbearing walls, but that does not mean that there can’t be complications. Before you embark on a home improvement project, it is always advisable to consult a structural engineering company.
Wall removal may seem like a small job for a structural engineer, but it is necessary. They will come to your home, discuss your ideas for an open plan livingspace, identify any loadbearing walls or party walls and advise you on how to deal with them. For example, when you remove a structural wall that is supporting a wall above it, you have to insert a beam to support the weight. You may also need to leave a small nib or section of the original wall at either end to support the beam.
If you are not removing any supporting walls, the structural engineer will simply provide a short report, diagram, and letter that states the wall can be removed. You need to keep this on record for when you want to sell the property. If you are removing a supporting wall, you will need Building Regulations approval. The structural engineer will provide a diagram and a report, with all the necessary structural design elements, that you will need to submit to the council to obtain building regulations approval. A building inspector will visit your home to ensure that the supporting beam has been correctly installed and meets British Standards for design. This is a legal requirement and essential for your insurance. Once you have your structural drawings and have obtained building regulations approval (if needed), the actual removal of an interior wall should not take more than a week.
What about party walls?
Semi-detached and terraced houses share walls and when you remove interior walls, your new beams may have to rest on these party walls. In many older properties, these party walls are not able to support the extra load. If this is the case in your home, you will have to support your beam with steel columns or brick piers. You need to plan for this eventuality as it could mean extra costs, building time and disruption.