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What is a Loft Extension?

A ‘Loft Extension’ is an extension from the roof of the building that is usually built vertically from the slope of an existing roof. There are four common types of ‘Loft Extension’ three of which involve structural changes to the building and therefore usually engage the Party Wall Process. These are a Dormer loft, a Hip to Gable loft and a Mansard loft. Each of these types of ‘Loft Extension’ adds floor space to the dwelling, whereas the fourth type known as a Roof Light loft, neither adds to nor alters the existing floor space but rather increases the light to transform a dull living space into a bright one.

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    Dormer Loft

    In Icon Surveyor’s experience, the most common type of ‘Loft Extension’ is that of a Dormer Loft. Building this type of ‘Loft Extension’ may not require planning permission. It usually requires a few simple alterations, enables windows to be installed and generally adds a generous amount of additional living space, is cost-effective and thus adds value to the property. The average cost to install a Dormer Loft is between £30,000 and £60,000, however, the L-shaped Dormer loft is usually more expensive weighing in at approximately £40,000 to £75,000

    Hip to Gable Loft

    Another popular type of ‘Loft Extension’ is known in the trade as a Hip to Gable loft. This is generally used to extend the lofts in detached or end-of-terrace properties.  It is popular because it tends to blend in with the existing building and can make a marked difference to the internal living space. This option is slightly more expensive than a Dormer loft but cheaper than a Mansard loft. The cost of this type of ‘Loft Extension’ ranges from between £32,000 and £60,000

    Mansard Loft

    The final ‘Loft Extension’ that Icon Surveyors will consider in this blog is that of a Mansard loft which is usually built by way of raising the party wall that a building owner of a terraced or semi-detached house shares with an adjoining neighbour. These types of ‘Loft Extensions’ are used in older properties as they tend to blend in well. This type of ‘Loft Extension’ is the most likely to require planning permission and can be more costly than the others that have been mentioned. A Mansard loft is the most expensive of the three common types of ‘Loft Extension’ usually ranging from £40,000 to £70,000.

    Loft Extensions are very common. Like many structural renovations, Loft Extensions require a considerable amount of planning under the building regulations applicable in England and Wales, which must be complied with. Such works, if carried out in semi-detached or terraced properties will invoke the Party Wall Act. Due to the need to expose, cut into, away from or raise the Party structure. The building owner always is required to comply with the applicable building regulations, under the Party Wall etc. Act 1996, they are also required to serve a Party Wall Notice, within a specified time limit, before the commencement of any works. In addition, when carrying out works of this type, it is not unusual for further requirements under the Act, to come into play. Icon Surveyors will consider some of these provisions below.

    It should be noted that Party Wall procedures are separate from planning permission and building regulations, both of which, must be complied with.

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    There’s a huge amount to bear in mind when you’re undertaking construction works, and it can be a challenge to make sure all the legal bases are covered. The good news is that specialist party wall company Icon Surveyors is here to help with up to 15 minutes of FREE telephone advice with an experienced party wall surveyor in London or Surrey. There’s no obligation, and we’ll put the advice in writing if you need it.

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    We’ve compiled a list of the most commonly asked questions from our clients to make sure you have all the information you need to make informed decisions about your project. From pricing to scheduling, we’ve got you covered.

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      Do I need planning permission for a ‘Loft Extension’?

      In our experience, the more popular ‘Loft Extensions’ such as the Dormer loft or in some cases a Hip to Gable loft is considered as permitted developments meaning that planning permission is not required. However, certain provisions must be followed when building a ‘Loft Extension’ on a terraced or semi-detached house. For example, it will not be permitted development if it is more than 40 cubic meters in size, or if the ‘Loft Extension’ goes beyond the plane of the existing rooftop on the principal elevation of the property.  Finally, the building owner must ensure that the ‘Loft Extension’ is not higher than the existing roof. For confirmation on if planning is required, we would always recommend you confirm this with your local authority.

      In Icon Surveyor’s experience, a building owner who plans to install a Mansard Loft will likely need to apply for planning permission. Icon Surveyors would always recommend that a building owner checks with the local Planning Authority to ensure whether planning permission is required.

      As a ‘Loft Extension’ is often used to increase the living space in terraced or semi-detached properties situated in built-up towns and cities thus, a building owner will be required to comply with the provisions of the Party Wall Etc. Act 1996. This may not be limited to but will most certainly include the service of a Party Wall Notice on any affected adjoining owner. It may also include a Party Wall Agreement or Award that is usually drawn up by a ‘Party Wall Surveyor’.

      A Party Wall for the purposes of a ‘Loft Extension’ is a wall that separates two or more buildings. This could be a wall that adjoins properties such as terraced or semi-detached houses or ceilings and floors in apartment buildings. As a rule of thumb, any building works being carried out that has the potential to cause damage to an adjoining neighbour’s property is for all intents and purposes, a Party Wall to which the provisions of the Party Wall Etc. 1996 apply.

      The Party Wall Etc. 1996, makes provision for building works about party walls, excavations and construction that is being carried out in the vicinity of certain buildings or structures in England and Wales. The purpose of the Act is to enable a building owner to exercise the right to carry out certain building works on their property whilst at the same time protecting any neighbouring property that may be affected by the building works being carried out. The effect such works may have on an adjoining neighbour includes, but is not limited to, inconvenience to the neighbouring party, for example installing scaffolding on a neighbouring party’s land to build a ‘Loft Extension’ causing an inconvenience that may warrant compensation, or, causing damage to the building whilst the ‘Loft Extension’ works are being carried out.

      There are three key functions the Act provides for, the first is to ensure that any building owner who proposes to carry out a ‘Loft Extension’ does not start any of the works without first notifying all adjoining neighbours that may be affected by the works, by way of a Party Wall Notice. The second function is to ensure that an agreement confirming how the works to the ‘Loft Extension’ are to be carried out, in other words, consent in writing must be gained before any works can commence. This can be accomplished by way of the building owner and adjoining owner reaching an agreement between themselves or through the appointment of a Party Wall Surveyor, who will draw up and agree on the Party Wall Award. The third function is to compensate any party that has incurred any form of damage or inconvenience.

      By its very nature a ‘Loft Extension’ will involve some form of intervention with the structural frame of a building. Therefore, under section 3 of the Act a ‘Party Structure Notice’ must be served by the building owner who proposes to carry out a ‘Loft Extension’ on any adjoining ‘owner’ whose property may be affected by the proposed works.  A building owner may draw up the Party Structure Notice in accordance with the requirements laid out under section 3 of the Act. Alternatively, the building owner may wish to appoint a Party Wall Surveyor to carry out the building owner’s mandatory obligations under the Act.  A Party Structure Notice must be served on any adjoining owner who may be affected by the proposed installation of a ‘Loft Extension’ at least two months before the date on which the proposed works will begin. A building owner should be aware that any works that have not commenced within 12 months of the day the Party Structure Notice is served will cause the Party Structure Notice to cease to have an effect. In other words, the works cannot commence without carrying out all of the procedures pertaining to an adjoining owner’s consent to install the ‘Loft Extension’.

      After receiving a Party Structure Notice an adjoining owner has three options all of which must be responded to in writing within one month of the date the Party Structure Notice was served. An adjoining owner can consent to the proposed ‘Loft Extension’, dissent to the ‘Loft Extension’ being built and appoint their own Surveyor to act on their behalf, or dissent to the ‘Loft Extension’ being built and appoint the Building Owners Surveyor as the Agreed Surveyor, this Surveyor will then act impartially on behalf of both parties and agree a Party Wall Award. The works will then be allowed to commence. If the adjoining owner refuses to consent to the ‘Loft Extension’ being built or fails to respond within one month, under the provisions of the Act a dispute will be deemed to have automatically arisen and under section 10, the building owner has a duty to appoint a Party Wall Surveyor to adjudicate the matters in disagreement. An adjoining owner also has the option to appoint their own Party Wall Surveyor, the costs of which will be borne by the building owner. Once consent to carry out the proposed ‘Loft Extension’ has been obtained, a building owner may commence with the proposed installation works.

      A Party Wall Surveyor is an impartial advisor who is appointed under section 10 of the Party Wall Etc. Act 1996, to determine disputes in accordance with the procedures set out in the Act. Thus, a credible Party Wall Surveyor is usually professionally qualified and accredited by a regulatory body such as RICS or the CIOB. There are several roles that are undertaken by a Party Wall Surveyor appointed to oversee a Loft Extension, these include, but are not limited to; drawing up and ensuring effective service of a Party Structure Notice; carrying out inspections of both a building and adjoining owner’s property; drawing up a schedule of condition report that have been determined from the inspections; resolving disputes that may arise between the parties by drawing up a Party Wall Agreement or Party Wall Award in response to a Party wall Notice. The Award will incorporate protective measures for all parties to the Award. In some cases, the Party Wall Surveyor or Surveyors may appoint ‘Checking Engineers’ to require funds held on account or request the installation of movement monitoring.

      A Party Wall Award, sometimes referred to as a Party Wall Agreement, is a statutory document drawn up by a surveyor that stipulates certain terms and conditions that a building owner or adjoining owner must abide by in order for works Under the Party Wall etc. Act 1996, to be carried out.

      A Party Wall Award is, under section 10 of the Act, a mandatory requirement for parties that are considered under the Act to have fallen into a ‘dispute’. It is intended to be a form of ‘Dispute Resolution’, thus, a mechanism that includes precautionary measures and protections against disputes that have arisen, so that an adjoining owner remains protected, and a building owner may commence with their right to carry out any works under the Act.

      The Award is usually compiled in three sections, these encompass; the Award itself contains a description of the permissible works; a Schedule of Conditions which usually contains a written report with accompanying photographic evidence of the pre-work condition of the properties that may be affected by the works, and; Drawings together with any additional information, i.e. Structural Calculations.

      In Icon Surveyor’s experience, A Party Wall Award is often called for when consent is being sought from an adjoining owner for a proposed installation of a ‘Loft Extension’. This is because such works usually involve some form of inconvenience to an adjoining owner who wishes to be fully protected against both the inconvenience that is likely to be caused and any potential damage to the adjoining property that may arise due to the works being carried out.

      The installation of a ‘Loft Extension’ can be more complex than initially envisaged. If you find yourself with unanswered questions, we are here to help!

      Here at Icon Surveyors, we provide a 30-minute free consultation to any owners who may be affected by the Party Wall Act. We work throughout the UK specialising in all matters relating to the Party Wall Etc. Act 1996.

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