When additional space is needed in a Dublin home, two of the most popular options available to homeowners are a house extension and an attic conversion. Both approaches can add significant living space to a property, but they differ considerably in the type of space they create, the planning requirements involved, the structural work required, and the overall impact on the home.
Understanding the differences between these two options is an important first step in determining which is the right solution for a particular property and set of requirements.
A house extension can take a number of forms depending on the property type, the available space and the planning context. Rear extensions, side return extensions and double-storey extensions are among the most common types carried out in Dublin, with each offering a different approach to increasing the usable footprint of the home. A review of what is involved in planning a house extension in Dublin can help in understanding which configuration may be best suited to a given property and site.
Rear extensions are particularly well suited to properties where the ground floor living space is the primary constraint, as they allow the kitchen, dining room or living room to be extended outward into the garden.
One of the key advantages of a house extension is the opportunity it presents to reconfigure the ground floor layout of the home. Where an extension is combined with internal remodelling, it becomes possible to create a fully open-plan ground floor that is significantly more functional and practical for modern family life.
This type of ground floor transformation is not achievable with an attic conversion, which adds space at the top of the house without affecting the existing layout on the floors below.
An attic conversion makes use of the existing roof space above the house to create an additional room or rooms. The most common types carried out in Dublin include dormer conversions, hip-to-gable conversions and Velux conversions, each involving a different approach to creating usable headroom within the roof space. More detail on the different configurations available can be reviewed through the attic conversions page, which covers the options available for a range of property types across Dublin.
Attic conversions are particularly well suited to properties where the ground floor space is considered adequate but an additional bedroom, home office or bathroom is required. They are also a popular choice for properties where garden space is limited and the footprint of the house cannot be extended without a significant loss of outdoor amenity.
However, an attic conversion does introduce a new floor level to the house, which means that an additional staircase is required to be provided. This staircase will typically take space from the existing landing or from one of the bedrooms on the floor below, and this loss of space is required to be factored into the overall assessment of the option.
Many house extensions in Dublin can be carried out under permitted development rights, provided that the extension meets the size and design criteria set out in the relevant regulations. Where these limits are exceeded, a full planning application is required to be submitted to Dublin City Council. The outcome will depend on factors including the size and height of the extension, its proximity to boundaries and its impact on neighbouring properties and the streetscape.
Attic conversions are similarly subject to planning regulations. In many cases, a Velux conversion can be carried out without planning permission where the roof structure is not being altered. However, dormer and hip-to-gable conversions will typically require planning permission, and the design of any dormer is required to meet the criteria set out in Dublin City Council development guidelines.
A house extension requires a new foundation to be constructed and a structural connection to be made between the new extension and the existing building. This typically involves the installation of a steel beam to support the opening between the existing house and the extension, and the new extension structure is required to be designed to suit the ground conditions at the site. A structural engineer and a reputable building contractor are required to be appointed to manage this aspect of the project correctly from the outset.
An attic conversion does not require a new foundation, but it does require the existing roof structure to be assessed and, in many cases, modified to create usable headroom. In older properties, the roof may be of a traditional cut-rafter construction that can be adapted more readily, while more modern properties with trussed rafter roofs will typically require more extensive structural modification.
A structural engineer is required to be appointed to assess the existing roof structure and to design the modifications required to create a safe and compliant converted space.
The decision between a house extension and an attic conversion depends on a number of factors that are specific to each property and household. Key considerations that are required to be assessed include:
● The type of space that is needed. An extension is better suited to increasing ground floor living space, while an attic conversion is better suited to adding a bedroom, bathroom or home office at roof level.
● The size and orientation of the garden. Where outdoor space is highly valued, an attic conversion may be preferred as it does not reduce the size of the garden.
● The existing layout of the house. Where the ground floor layout is considered inadequate and a reconfiguration is required, an extension offers the opportunity to address this at the same time as adding space.
● The roof structure and pitch. Not all roofs are suitable for conversion, and a survey is required to be carried out to assess whether an attic conversion is feasible before the option is committed to.
Q: Which option adds more value to a Dublin home?
Both options are capable of adding significant value to a Dublin home, but the extent of this depends on the nature of the space created and the needs of buyers in the local market. An additional bedroom created through an attic conversion and a large open-plan kitchen extension at ground floor level are both recognised as strong value drivers across many Dublin neighbourhoods.
Q: How much garden space is required for a house extension?
Planning regulations typically require a minimum area of private open space to be retained at the rear of the property. This varies depending on the property type and size, and the specific requirements for a given site are required to be confirmed with Dublin City Council before the size of the extension is finalised.
Q: Can an attic conversion be carried out on a terraced house?
Attic conversions can be carried out on many terraced houses in Dublin, but feasibility depends on the pitch and construction of the existing roof. A structural survey is required to be carried out to confirm whether the roof is suitable for conversion.
Q: Is a house extension or an attic conversion quicker to complete?
In general, an attic conversion is completed more quickly than a house extension, as the construction involved is more contained and does not require a new foundation. However, the duration of either project depends on its size and complexity, and a realistic programme should be discussed with the builder at the outset.
Q: Can both a house extension and an attic conversion be carried out at the same time?
In some cases, it may be advantageous to carry out both at the same time, as this can reduce the overall period of disruption and may result in efficiencies in the construction process. This approach should be discussed with the builder and, where applicable, with the planning authority before a decision is made.