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What is the cost of a loft conversion with a bathroom?

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What is the cost of a loft conversion with a bathroom?

Loft conversions present the perfect opportunity to add an extra bathroom to to your home. This will in turn put a significant amount of additional value on to your property, but what is the cost of a loft conversion with a bathroom?

The best way to find the cost of a loft conversion with a bathroom is to speak to a specialist in your area. Tell us about your project below and we can put you in touch with installation experts in your area - for FREE. 

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How much will it cost to add a bathroom to a new loft conversion?

There are three principal things which dictate the cost of a loft conversion and these are:-

  • The size of the conversion so the internal space
  • The style of the conversion; a roofline Velux loft conversion cost can be as little as £15,000 to £20,000 but a complex dormer loft conversion or a Mansard loft conversion could eventually end up costing somewhere around £40,000 to £50,000 on average
  • The internal accommodation which is one of the biggest influencers on cost often adding as much as £20,000 to the overall bill

The cost that a bathroom will add to your loft conversion will depend on the size of the bathroom, the choice of fittings and where the bathroom is situated in the loft conversion. If you can position the new bathroom above a bathroom on the floor below then this can save a considerable amount of time and money by avoiding the need to re-route water pipes and plumbing to a new location within the roof space.

Why are homeowners investing in loft conversions?

Judging by the amount of loft conversion companies that come up on any Google search, loft conversions are as popular as ever and this is because they offer some significant advantages particularly over rear or side extensions.

These include:

  • Loft conversions make use of existing space which is redundant avoiding a completely new build
  • Not every loft conversion requires planning permission
  • They offer an alternative to a side extension which may not even be possible if the house is terraced or a rear extension both of which could already have been done
  • Extending in the property in any direction almost inevitably means losing either garden area or parking space making an extension something of a trade-off
  • Pound for pound for the accommodation gained, a loft conversion offers the best value for money compared to an extension and the uplift in the value of the property after the work has been done is very attractive too; industry figures suggest an increase of anywhere between 20% and 25%

What are the options when fitting out new loft accommodation?

The choices of what you can do with the new space are virtually endless and, of course, if you avoid fitting kitchens or bathroom which are much more of a permanent feature, then your accommodation can change to suit your lifestyle and the needs of your family. A home gym can become a rooftop cinema and media room or morph into a much-needed home office or studio to accommodate a new business idea. Adding a more permanent feature like a kitchen or bathroom is also very popular with bathrooms probably the most common choice of the two.

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What are some of the considerations when adding a bathroom to a loft conversion?

A new bathroom either as an added family bathroom or as an en-suite to a new bedroom is one of the most popular choices of internal fittings for a new loft conversion space. Small loft conversions convert well into a family bathroom or if you already have enough bathrooms then you can create a master bedroom with en-suite attached. Here are some of the specific considerations you should think about when adding a new bathroom to your loft conversion:-

  • Bath or Shower? – a bathroom doesn’t have to involve either a bath or a shower, it could simply include a basin and a toilet. Many bedrooms in older period properties often had a washbasin and this can be very convenient. Fitting baths and/or showers requires clever use of the space available. A bath will take up much more space than a shower, however, if the loft conversion has a sloping ceiling then this is usually a great place to locate a bath as the limited headroom doesn’t matter and this area would otherwise be redundant. Showers take up less space but you do need a full-height ceiling to accommodate a shower. If the loft conversion is dedicated solely to a new bathroom then most people have both a bath and a shower; a bath is particularly useful if it is a family bathroom and you have young children
  • Extending and plumbing – plumbing is always a key consideration when you are planning a new bathroom in your loft conversion as the work will have to accommodate the existing plumbing in the house. It is easiest when locating the bath to put it as close as possible to the existing supply and waste pipes; this will save significant labour costs as you will not need to move or extend any of the current plumbing. These pipes are usually located to the side or rear of the house and this normally dictates the placement of the bath and shower fittings. Waste pipes are larger pipes than supply pipes and these can be challenging to move around or bend around corners. They also require a specific fall or gradient to allow the waste water to drain away properly. It is therefore ideal if possible to avoid moving or relocating waste pipes or keeping any changes to an absolute minimum
  • Water supply – householders worry about the water supply to the loft space but it is easy to solve this and avoid the hassle of fitting a water tank to a small area. Most showers fitted will be electric showers and you could also consider upgrading your boiler to a combi boiler as this will really help to heat the water instantaneously as well as making it much easier to provide water to other fittings like a hand basin
  • Ventilation – ventilation is a key factor in your new bathroom otherwise the room will suffer from excessive condensation and will eventually become damp and mouldy. An extractor fan is one option but they are noisy and can impact on the peace and quiet of the bedrooms on the floor below. Velux windows or skylights can offer you the ventilation that you need as well as allowing natural light to flood in. Some of the newest designs from Velux feature remote control options which you can open and close at the touch of a button making them quick and easy to operate when you use your new bathroom. These also have a rain sensor so if you forget to close them after you have taken a bath or shower then they will do the job automatically if it starts raining
  • Choice of windows – bathrooms whether a family bathroom or en-suite can generate a lot of steam so PVC frames for your roof windows are often a better option than wood. Some PVC options have a ventilation system at the top of the frame so you can allow fresh air in and the steam out without even having to open the window, others have specially designed channels at the bottom of the window which allows condensation and any accumulation of water to drain away
  • Lighting – natural light is always the best option over electric light. Theoretically, you don’t need to include windows in your loft conversion project if you are only fitting a bathroom in the space and no other accommodation. However, the whole aspect of the room will be vastly improved if you allow natural light in and you supplement this with artificial light sources on gloomy days and at night. Using LED lighting, you can generate light which is similar to daylight even when it is dark, and spotlights fitted into the new ceiling will sit flush and not abut into the room taking up valuable head height. There are waterproof and water-resistant versions for steamy bathrooms
  • Locating a toilet – your new bathroom doesn’t have to feature a toilet but if it does, it is easiest to place it as close as possible to the current waste outlet. When a toilet is flushed, the waste enters the sewer or septic tank via the main drain line so it makes sense to locate the toilet above your existing toilet or as close to it as possible. There are other options if the plan of your bathroom features a toilet sited well away from existing pipework. One of these is a macerating toilet which is a toilet designed to go in any location where there is no easy access to drainage. The other is an up-flush toilet. Standard toilets work by flushing gravitationally downward to your pipes, an Up-flush toilet discharges from the back of the toilet and into a pump that houses a macerator which grinds up the waste and pumps it up PVC piping to your existing soil stack. This can be located metres away allowing you to site an Up-flush toilet wherever you want. Visually, an Up-flush toilet will look the same as a standard toilet just with the addition of a pump which is a small white unit that either sits on the floor behind the toilet or connects to an extension pipe which can hide the pump behind a wall. The latter option will make this type of toilet virtually indistinguishable from a standard toilet

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Frequently Asked Questions

Will I need planning permission to fit a new bathroom to my loft conversion?

What you do with the internal space in your new loft conversion is not usually a factor triggering the requirement for planning permission, these are the issues which can determine whether or not a planning application is necessary:-

  • The size of the loft conversion
  • Whether your home is listed or in a conservation area
  • How much development has already taken place at the property
  • How much you are going to change the structure and appearance of the existing roof – this can come down to the fine detail, for example, the size of the dormer windows and how far they abut from the roof plane

Even if a loft conversion does not require planning permission and falls within ‘Permitted Development’, it will still require compliance with current building regulations and the works as they progress must be checked by a local Building Inspector.

How can I fund a loft conversion with a new bathroom?

There are several financing options available to fund a new loft conversion particularly if you do want to fit a new bathroom so are looking at generally higher costs than some other interior accommodation choices. These include:-

  • Approaching your current mortgage lender for further borrowing which is often called a Home Improvement Loan or Further Advance. You will need sufficient equity in the property to support the sum borrowed before the works take place and not rely on the uplift in the property value once the loft conversion is finished. You must also satisfy your lender’s affordability criteria to show that you can meet the increased monthly payments which are usually spread over the remainder of the mortgage term
  • Remortgage your property to take advantage of a better interest rate deal. Householders who remortgage often use this process an opportunity to raise funds for refurbishment works with their new lender based on the equity in the property
  • Equity Release which is a route favoured by older homeowners who have usually paid their mortgage off but will like to raise capital sums against the value of their home. These do not have to be used exclusively for property upgrade projects
  • Finance offered by your loft conversion company or building contractor is another option. Some of the larger contractors work with third party financial institutions to provide lending choices rather like the type of finance which may be offered when you buy white goods, a new three-piece suite or a new car. Eligibility is subject to the usual status requirements and may require a deposit

If you add a new bathroom to your loft conversion then this may open up other possibilities to also change the arrangement of the accommodation on the floor below. A favourite is to use the smaller and redundant existing bathroom to add onto an adjacent bedroom to create an en-suite. Loft conversions usually open up the possibilities of altering other rooms within the home creating a dual benefit.

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