The primary factors that drive the value and selling price of a property up are location and usable area. These are the 2 main considerations that should be considered when selecting a property or site on which to develop. Leaving the ‘location’ aspect to one side for now, usable area is a very shrewd way of increasing value and in some cases this can be accomplished fairly easily.
I stress the term ‘usable’ area because (to use an example) if a converted loft is not compliant with building and fire regulations, the additional space cannot be marketed as such. This often works in a private property developer’s favour because carrying out the work to make the room compliant might not involve that much work. An example of this might be the installation of a fixed stairway and fire doors. Expenditure of a few thousand pounds to have this work done can release tens of thousands in eventual property value.
Another way to increase internal area is to extend. It’s important to have quite a good idea of the size, location, shape and design of the extension before even applying for planning consent or a Certificate of Lawful Development. A design will be needed (this doesn’t have to be professionally produced at this stage) to illustrate what is planned. Clearly if the property has not even been purchased at this stage, the consideration must be carried out when evaluating the property.
What I’m working my way round to write about is planning the foundations of that extension. I hasten to add that any detailed advice on this subject should be directed to either a Building Surveyor or a Building Engineer. That said, it’s extremely useful if you can carry out a very quick assessment of the property yourself prior to purchase so that you have an idea of the viability of the project. One of the issues I have come up against recently is foundation depth due to the very close proximity of tree roots from a neighbouring property. To ensure compliance with building regulations (and compliance WILL be checked by the purchasers Solicitor when the property is being sold onwards) the foundations must go down to minimum depths below ground level. It is not unheard of to find that trees up to 30 metres away from a property can have an effect on the foundations. Therefore it’s very important that this is considered in your overall property plans.
Conventional strip foundations are not suitable when having to dig so far below ground level. Deep strip or reinforced trench fill will be better suited. Pile foundations can also be used and might be more economical.
The illustration and table below (please excuse the standard of my drawing) provides a method of assessing how deep the foundations must go to be sufficiently strong enough to withstand the effects of nearby tree roots. In addition to this, drains must also be incorporated into the design of the foundations. Again, a Building professional will be able to provide more detailed information on specific situations.
Foundation depth may seem excessive, but the property or extension must be on a base that can withstand not only the penetration of tree roots but the effects trees have on their surrounds. Large trees can draw hundreds of litres of moisture out of the ground every day. This has the effect of soil shrinkage which often results in property damage due to the slight ‘drop’ in the side of the property closest to the tree. If the tree is removed, the opposite effect occurs and the effected side of the property lifts slightly which can also cause damage.
Another factor to consider when evaluating the proximity of trees is Tree Preservation Orders (TPOs). You might consider the work involved to put in deep foundations is worth carrying out, however the tree roots must not be damaged as this might harm the tree. In some circumstances, a local planning authority might consider the removal of a tree to be worth the sacrifice if the development is important. To be realistic though, it’s unlikely a private development would be considered in this way.
If you think the close proximity of tree roots will compromise your proposed development, speak to a Building professional or the local building control department.