Are the internal walls taking any loading?
When having a new loft extension or conversion it is important to remember that the load on your house is going to increase by at least 10%. It is very important at the design stage to figure out how this entire load is going to be evenly distributed throughout the house.
Now if your house has the first type of roof I mentioned earlier (the traditional timber roof) there’s a high chance that one or more internal walls are taking some of the load from the roof. However, if you have a new house the chances are that the internal walls aren’t.
Of course I structure nearly all loft conversion so that any extra loadings don’t need support from any internal walls. However, if there are some internal walls available doesn’t it make sense to use them? Using these walls can save you money as the design can be kept as simple as possible.
The first thing we would have to do is find out which of your internal walls are taking the load from the roof. Any walls that are blockwork or built of solid brick are likely contenders whereas the “hollow-sounding” timber walls are often just partitions. Though this is not always the case, many houses from the Victorian era and before have timber walls which are sometimes structural.
Alternatively, it may be more simple just to design the new loft floor so it covers new beams built in the loft, meaning that it wouldn’t require any support from internal walls.
Where will the new stairs go?
One very important factor when thinking about a new loft is how you’re actually going to get to it. Fitting in stairs can prove more trouble than you think, especially if you have a small house.
With many traditional houses from the Victorian era this shouldn’t prove much of a problem because the new stairs can usually be fitted directly above the existing ones, thus not much room will be lost. This is also similar with semi-detached houses where the stairs usually run parallel to a side wall. Although it is easy to install the new stairs above the existing staircase it may prove to be more difficult than expected.
As with most semi-detached houses the roof will be hipped. Thus there will be no room to climb the stairs when at the top. A simple solution to this is getting us to build a large side dormer or doing a hip-to-gable conversion. However, if you don’t fancy any of these it is likely that the stairs could in theory be placed anywhere below the loft.
Of course that depends on whether there is enough room to place the stairs. If there isn’t enough space to fit normal stairs it may be possible to fit a compact staircase. What must be remembered about this, however, is that although they save space they are not particularly popular with Building Control and so would have to be used as a last resort; you should be aware that even then they still may not be accepted.
Is there an entrance hall?
Fire regulations are very important to follow when thinking about any type of extension or conversion. The layout of the ground floor and the position of the main hall door can have a major impact on the cost of getting a new design to comply with the fire regulations.
An ideal ground floor layout would have an entrance hall leading in from the front door to the main stairs. If your house doesn’t have this layout then it will have to be redesigned before we can start work on the loft. It is also important to consider any extra internal walls being built during the construction process. These walls will act as the main defence if a fire were to occur.
Are there tanks and pipes that need to be relocated?
Unfortunately it is quite common in many lofts for the large cold-water tank to be placed right in the middle of your loft. It is extremely important to remember that everything in your loft is going to have to be relocated, at least for the duration of the construction. That means clearing out all of the clutter and other objects that are currently residing in your loft.
Things such as boilers and tanks, however, present a more problematic situation. These cannot simply be moved as that would cut off the heating around your home. Tanks and pipework can usually be successfully relocated to the corners of the loft, out of sight in a cupboard, or some similar accommodation.
If your tank is getting on a bit it may be even better simply to get rid of it. Many people nowadays are choosing to scrap their tank and install an unvented hot-water system such as a Megaflo pressurised system or combination boiler.
Roof conditions
Before starting the construction it may be a good idea for us to survey the condition of your roof. Any defects in the roof will have to be repaired before construction commences. If you’re planning on converting your loft into a new bedroom it is incredibly important to check for defects such as water leakage and missing tiles. Such things can damage the newly converted room within moments. Particular points on the roof such as the front roof slopes are more likely to be damaged and so must be repaired if this is the case.
Chimneys
It’s important to consider chimneys when thinking about the design of your loft conversion/extension. Obviously it would be unwise to place a roof window where a chimney stack eliminates the view.
It is also important to see if the chimney has been properly supported. Adding a large new dormer or other extension for the loft may interfere with the airflow for the chimney. Chimney stacks must rise 900mm above the ridge height so expanding the loft may mean you need to increase the height of the chimney stack. This is likely if your current roof is hipped and you’re thinking about a hip-to-gable conversion.
Party Walls
Most loft conversions utilise some large steel beams that are embedded into old party walls which naturally increase the loadings from the loft to the rest of the house. That is why it is important to have your party walls in tip top condition before starting the loft conversion.
Party walls are normally the length of a single brick thick (approx. 225-230mm) but this is not always the case. On older properties the length may only be half a brick thick due to builders saving money by laying bricks sideways. As you can imagine this is a serious flaw and must be attended to before building can commence.
However, although this may seem bad, things can actually be a lot worse. In some traditional Victorian terraces loft walls may be omitted completely! New party walls are often built from concrete blockwork and sometimes only 115mm thick. If your party walls are omitted or undersized it is obvious that they will need to be rebuilt.
If your house has chimney breasts in the roof these must also be considered before embedding the large steel beams. The problem here is that it is not permissible for the structural beams to be fitted directly into the chimney breast.
One more important factor involves your neighbour’s roof(s). If their loft has been converted/extended before, then the chances are they have steel beams in their party walls as well. The problem here is there may be a chance for beam-to-beam conflict. The beams need at least 100mm either end for support so it’s important to find out the position of your neighbour’s beams before advancing.
Main walls
Another aspect to consider before starting construction is the current condition and type of the main walls in your home. Properties before the 1930’s often have solid brick walls about 230mm thick or even solid stonework which can be more than 400mm thick. Houses built after the 1930’s often have cavity walls which are between 260mm and 300mm thick, whereas modern cavity walls incorporate a timber frame inner leaf.
Older buildings are more prone to defects which means there can be potential problems before the conversion. All walls must be checked for cracks and other defects before continuing, and any cracks must be followed up before additional loads can be applied.
Newer buildings are also at risk, however. The lightweight concrete blocks of the inner leaves have a maximum load bearing weight and so all of this must be considered before starting a loft conversion.
Roof Replacements
If, after our survey, we decide that it’s not advisable to have a loft conversion/extension with the current roof there are other constructions that can be considered. Sometimes it can be more beneficial to rebuild the roof from scratch.
If your current roof is too shallow to provide sufficient headroom then this may be the only option available to you. However, a downside of roof replacement is the need for planning permission. If, however, it is approved the replacement of your roof can begin.
Although it may seem like a huge and costly job to you it isn’t as dramatic or expensive as it may seem. In fact it won’t cost any more than an equivalent sized home extension.