Residential stock data and dataset on energy efficiency characteristics of residential building fabrics in Ireland

These data support the research article “Improving energy savings from a residential retrofit policy: a new model to inform better retrofit decisions” – (Mac Uidhir et al., 2019) [1]. This article presents 3 data sources which are utilised in conjunction with a detailed energy system model of the residential sector to explore policy pathways for residential retrofitting. Data is collected from the Central Statistics Office (CSO) and the Sustainable Energy Authority of Ireland (SEAI). The first SEAI dataset is compiled for Ireland in compliance with the EU Energy Performance of Buildings Directive (EPBD) [2]. Data is collected using the Dwelling Energy Assessment Procedure (DEAP) [3]. DEAP is used to produce energy performance certificates known as Building Energy Ratings (BER). A BER indicates a buildings energy performance across a 15-point energy efficiency scale, rated alphabetically from A1 to G, in units of kWh/m2 year. A BER is required for new buildings and the rent or sale of existing dwellings – therefore the database has consistently grown in size since its inception in 2006. The BER database contains 735,906 records of individual dwellings. The database includes detailed building fabric information across a range of different building types, year of construction, Main/Secondary space/water heating fuels, heating system efficiency, ventilation method and structure type (Insulated concrete form, Masonry, Timber or Steel Frame). The second SEAI dataset (PWBER) contains aggregated pre and post BER information for a sample of 112,007 dwellings retrofitted during the period 2010–2015; this database contains mean energy efficiency improvement (kWh/m2 year) for a range of retrofit combinations as they apply to nine distinct building archetypes. The third CSO dataset is compiled from census data, representing the frequency of building types by year of construction.

Timber or Steel Frame). The second SEAI dataset (PWBER) contains aggregated pre and post BER information for a sample of 112,007 dwellings retrofitted during the period 2010e2015; this database contains mean energy efficiency improvement (kWh/m 2 year) for a range of retrofit combinations as they apply to nine distinct building archetypes. The third CSO dataset is compiled from census data, representing the frequency of building types by year of construction. © 2020 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/).

Data
The supplementary SQL database attachment provided with this article contains detailed building fabric performance characteristics for 735,906 dwelling records. Informational data is provided for each record in the form of a description of the dwelling type (Apartment, Basement Dwelling, Detached Specifications Table   Subject Engineering (General) Specific subject area Residential dwelling energy performance characteristics and stock for Ireland. Type of data Microsoft

Value of the Data
This data provides transparency to model input parameters used in the evaluation of energy efficiency measures for residential dwellings in Ireland. The data provides a detailed source of building fabric information in a queryable format. Energy analysts can benefit from the detailed building fabric information, serving to aid in replication of residential energy efficiency analyses. Policymakers can also benefit from detailed analyses underpinning evidence-based policy support. This data can be used to gain insights into the link between energy performance of specific building fabrics and the associated net improvement to building energy efficiency.
house, End of terrace house, Ground-floor apartment, House, Maisonette, Mid-floor apartment, Midterrace house, Semi-detached house, Top-floor apartment), year of construction, dwelling location (postal code for Dublin and City/County description for all other counties), date/purpose of the BER assessment (Grant Support, New Dwelling, Private Letting, Sale, Social Housing Letting, Unknown, Other). Building fabric data is provided in the form of U-Values (W/m 2 K) and surface area (m 2 ) for each dwelling's walls, roof, floors, windows and doors. The number of building stories, ground floor area (m 2 ), heating system efficiency and the main/secondary space/water heating fuels are also provided for each record. This data is gathered for Ireland in compliance with the EU EPBD [2] using DEAP [3]. The datasets within this article provide CSO census [4] and BER data on the number of dwellings by type, year of construction and BER grade category ( Table 2). This data is presented in Table 1 and Table  2.
Data specifying the total number of dwelling types, by year of construction, is presented in Table 1. This data was collected as part of the national census completed in 2016. The energy performance of building types is not included in this data.
Data specifying the total number of building archetypes, by year of construction and energy performance grouping is presented in Table 2. This dataset is collected as part of Building Energy Rating (BER) programme operated by SEAI. A BER is compulsory for all new dwellings, dwellings being sold/ rented, dwellings in receipt of an SEAI energy efficiency grant.
The BER database, included as supplementary material, represents a range of 140 individual building characteristics as they apply to 735,906 dwellings. The average U-Value (W/m 2 K) for walls, roof and windows, for each of the nine dwelling archetypes and year of construction bracket, is shown in Tables 3e5 respectively. A complete list of building characteristics is included and further described in Table 7.

Experimental design, materials, and methods
This section outlines the steps required to acquire, process and analyse the data referenced in this article.

Census data on housing in Ireland
The CSO provide direct access to 2016 census results for building type by year of construction through an online portal [4]. CSO survey definitions for building type differ from other sources and are therefore aggregated into three building types (Detached, Terraced, Apartment), as shown below in Table 6.

BER database
This process describes the acquisition and filtering procedures to produce the included BER input database. Tables 2e5 are derived directly from the filtered BER database.
2.1.1 The Sustainable Energy Authority of Ireland host a public national depository of all BER records, available for download in excel format [5]. This format is not suitable for analysis and required further processing to produce queryable database in SQL format.

This Raw Data is imported into a blank Microsoft SQL database table using SQL Server Integration
Services (SSIS). SSIS is used for complex data transformation and managing/filtering data [6]. This process allows all 735,906 records to be queried individually. A series of scripts are then utilised to manage and filter the database, adding unique record ID's for each record in the database and removing unwanted outliers. Each script is provided with this article and its function described here.