Property Elements In this section we will look at the different Property Elements and how to identify and assess them.
Property Elements • This section of the training will cover a variety of property elements • Flats/Maisonette • Floor and roof heat loss types • Extensions • Room in Room • Basements • Conservatories • Porches • Alternative walls • Windows • Lighting
Flat or Maisonette Technically there is no difference between a flat and a maisonette in RdSAP, the only difference is the description on the 1st page of the EPC. Stroma Certification uses the following definitions for these dwelling types as a guide : A flat is generally defined as a self contained residential unit within a larger structure, containing several self contained unit or units all sharing a common entrance. They are usually single storey dwellings. A maisonette is a dwelling which occupies 2 or more floors within a block. It can also be described as dwelling has its own access directly from the outside (i.e no communal corridor) but is not a stand-alone building.
Corridors • In RdSAP there are three corridor selections - None, Heated or Unheated • You will only be asked for the corridor type for flats and maisonette’s • If the corridor is unheated, measure the length of corridor adjacent to the flat, including the flat door • The length of the unheated corridor must be included in the total heat loss (HLP) measurement for the flat
Floor Level • It is very important to correctly identify whether the flat is: • Basement • Ground floor • Mid floor • Top floor • Even if the lowest floor level of the dwelling extends over more than one floor enter it as the lowest floor e.g. ground and first floor flat would be entered as ground. mid floor flat
When assessing a flat the detachment may not be obvious If the Access Corridor is unheated: Flat A is an end terrace Flat B is a mid terrace If the Access Corridor is heated: Flat A is an enclosed end terrace Flat B is an enclosed mid terrace Definition of Enclosed Property
Floor heat loss type In RdSAP it is necessary to indicate what type of heat loss the lowest floor of a dwelling has. This applies to all dwelling types • houses, bungalows, flats, maisonettes • he options for floor type are • Ground floor • Above partially/intermittently heated space (Commercial Premises) • Above an unheated space (basement, Garage) • To external air • Same dwelling below (vertical extensions) • Another dwelling below (another flat below)
Floor heat loss type Ground floor • This will apply to most houses, bungalows and ground floor flats • It simply means the lowest floor of the dwelling is on the ground • If a dwelling has a basement which is not included in the assessment then the lowest floor will not be on the ground.
Floor heat loss type Above partially/intermittently heated space • This option should be used when the lowest floor or the dwelling or part of a dwelling (main/extension) is located over a commercial premises • It is termed partially or intermittently heated because commercial premises are assumed to have a different heating pattern to residential buildings
Floor heat loss type Above an unheated space • This option should be used when the lowest floor of the dwelling or part of the dwelling is over an enclosed space which is not heated, such as a garage or unheated basement
Floor heat loss type To external air • This option is to be used when the lowest floor of a dwelling, or part of a dwelling is exposed to the outside • Some houses and flats have a tunnel passing under the first floor through to the rear of the building
Floor heat loss type Same dwelling below • To be used when the lowest floor of part of a dwelling has been built over the existing dwelling, also known as a vertical extension. (These will be covered later )
Floor heat loss type • Another dwelling below • To be used when the lowest floor of the dwelling or part of the dwelling is above another dwelling • Commonly used for mid and top floor flats, but can also be used for flying freeholds, i.e. when part of a property is located over another property
Roof heat loss type • As with floors it is necessary to indicate what type of heat loss the roof of a dwelling has. • This applies to all dwelling types – houses, bungalows, flats and maisonettes • The options for roof type are • Pitched (slates or tiles), access to loft • Pitched (slates or tiles), no access to loft • Pitched (thatch) • Flat • Same dwelling above • Another dwelling above
Roof heat loss type • When assessing the roof type you are concerned with the dwelling being surveyed, not always the whole building. E.g. when surveying flats. • If you were to survey the ground floor flat of this building, what would you think is the most appropriate statement about the roof type?
Roof heat loss type Another dwelling above • This option is usually used for ground and mid floor flats. By selecting ‘another dwelling above’ the software knows there is another dwelling above the flat surveyed. • This option can also be used for under-dwellings and similar building arrangements where part of another dwelling is built over the property surveyed.
Roof heat loss type Same dwelling above • This option can be used when part of a dwelling has had an extension built above it, known as a vertical extension. (This will be explained in more detail later in this section.) • The roof type simply indicates to the software that there is no heat loss
Extensions • Many properties have extensions added to the original building. These can be identified separately in an EPC. But an extension doesn’t have to be a later addition to a property to be classified as such in RdSAP. For the purposes of RdSAP an extension is part of a property which has different thermal qualities to the rest of the house • This can be due to: • Age • Wall construction/insulation type • Roof construction/insulation type • Floor heat loss type
Extensions • RdSAP allows for 4 extensions, which is generally more than enough for the majority of properties. • If a property has one or more extensions separate information must be recorded for each of them. • For each part of the dwelling the following data should be collected: • Dimensions • Wall construction and insulation • Roof construction, insulation and heat loss types • Floor construction, insulation and heat loss type • Build date
Different roof types Main property – pitched roof Extension – flat roof Examples of Extensions
Extension Examples Wall construction • Main property – solid brick • Extension – cavity
Roof insulation Main property – insulation at joists, 250mm Extension – no access to loft, unknown insulation Extension Examples
Extension Examples Build date • Main property – 1900-29 • Extension – 1991-95
Extension Over A Garage • If a property has an extension over an unheated garage or similar unheated space, it should be entered as an extension on the lowest floor • This is because the garage is not included in the survey, and it is not possible to leave the lowest floor blank in the software. • The floor heat loss type should be entered as ‘over unheated space’ • If the garage is heated by the main heating system, it should be included in the survey
Vertical Extensions A vertical extension is an additional storey to a property which can not be accounted for as a room in the roof. Identify the vertical extension as an extension in the software, taking separate information for the whole extension area. • Specify the upper floor heat loss type as ‘same dwelling below’ • Specify the lower floor roof type as ‘same dwelling above’ Vertical extension Main property
If the vertical extension does not cover the whole dwelling the part of the dwelling below the vertical extension must also be identified as an extension in order to specify the roof type as ‘the same dwelling above’. Vertical Extensions Extension 2 Floor type: Same dwelling below Extension 2 Roof type: Pitched roof Main property roof type: pitched roof Main property floor type: ground floor Extension 1 floor type: ground floor Extension 1 roof type: same dwelling above Extension 2 Main Property Extension 1
Multiple Extensions Extension 2 Extension 3 Main Property Extension 1 Extension 4 Extension 5 Occasionally you may come across a house which has more than 4 extensions; in this situation you must ‘blend’ the extensions. Merge the areas with the most similar age, construction and insulation, and make use of the alternative wall facility where appropriate.
Mezzanine floors A mezzanine floor is usually an intermediate floor between two floors in a building. A mezzanine floor does not extend across the whole dwelling This means part of the property has more floors than the rest. It also means that the ceiling height for part of the dwelling is significantly bigger than the mezzanine section.
Mezzanine floors • When assessing a dwelling which has a mezzanine floor split the dwelling vertically • The split should separate the property into a part with the mezzanine and a part without the mezzanine • Specify one part as the main property and the other part as an extension • In the picture the mezzanine makes part of the property 2 storey, the remainder of the property is 1 storey. • The 2 storey section is the main property, 2 storeys are measured and entered into the software, with separate ceiling heights for each storey • The single storey section is entered as an extension with just 1 storey entered in the software, and the full floor to ceiling height entered as the ceiling height.
A room in a roof is defined by the following: Access must be via a permanent fixed staircase that one is able to walk up and down facing forwards. (This does not include fixed loft ladders). The height of the common wall must be less than 1.8m for at least 50% of the storey. Please note this does not include stud walls, gable ends or party walls. (The common wall is a vertical continuation of the external wall of the storey below.) If the common wall measures greater than 1.8m for more than 50% of the floor then it is classed as a normal storey. Measure floor area (internally); no need to measure room height or heat loss perimeter Room in a Roof
Rooms in Roof • Would this be a room in the roof? • Height of wall at eaves (common wall) is less than 1.8m • This is classed as a room in roof
If the 50% or more of heat loss walls at the eaves (common wall) are 1.8 metres high or greater , the space is classed a normal floor and you will need to take the measurements of wall perimeter (heat loss walls), room height and the floor area. Not a Room in the Roof
Why have room in roof? When you say a property has a room in roof it means the software makes the following assumptions • The wall construction is timber frame (i.e. the roof construction, rather than cavity wall, solid brick etc • The ceiling height is assumed to be 2.2m high. It can be difficult to get an average ceiling height for rooms in roof due to the sloping ceiling • The heat loss perimeter is based on that of the storey below. During test surveys carried out prior to the release of RdSAP, assessors were asked to measure the heat loss perimeter of the room in roof, but assessors came back with such varied results for the test properties that it was decided that this figure should be assumed to avoid too greater variation in ratings. Effectively, when you specify a room in roof, you are saying that the majority of heat loss for the storey is through the roof rather than the wall construction specified in the software.
Partially Insulated Roof Rooms Presently, RdSAP assigns a flat roof area, and the remainder as wall area, based on the floor area entered This is a useful estimation in most cases, however this may not prove sufficiently accurate in certain scenarios If it is judged the roof room vastly differs from the default values, the software allows areas and insulation to be recorded separately stud walls gable walls sloping parts flat ceiling parts It will also be possible to indicate in the software whether the room in roof is connected to another part of the dwelling i.e. extension.
Partially insulated roof rooms in some cases it is not possible to get the Roof Room insulation levels. This is when default values are used by the software.
Partially insulated roof rooms • If can only get access to certain parts of the insulation you can enter either; • All elements • Flat ceiling only • Walls and sloping parts
Partially insulated roof rooms • When you can get the details of ALL roof room insulation, the following data can be entered: • Actual area • Actual U-value
Is it a room in roof? Here are a few slides of properties • Do you think the top floor is a room in roof or another storey? • You will be able to tell from the photo, and not have to measure the common wall height • Assume that there is access via a fixed staircase to the top floor of the property.
Is it a Room in Roof? Yes • The dorma windows are built into the roof • The common wall stops at the top of the first floor • The common wall is 0m for the roof room
Yes This is a dorma bungalow The entire top floor is built within the roof structure, the cavity wall stops at the top of the ground floor The dorma window is likely to be constructed using timber Is it a Room in Roof?
Is it a Room in Roof? Yes • There are skylights in the roof of this property indicating there is an additional floor in this property • The common wall stops at the top of the 1st floor, so the whole top floor of the property is within the roof space
Is it a Room in Roof? • No • The common wall stops part way up the top floor but the window height is likely to be 2.1m • The common wall extends for more than 50% of the storey