Influence of building insulation on outdoor concentrations of regional air-pollutants Ulrik Smith Korsholm a, * , Bjarne Amstrup a , Thomas Boermans b , Jens Havskov Sørensen a , Shiyu Zhuang a a Danish Meteorological Institute, Research Department, Lyngbyvej 100, 2100 Copenhagen Ø, Denmark b ECOFYS, Built Environment Strategies, Am Wassermann 36, D-50829 Köln, Germany article info Article history: Received 15 June 2011 Received in revised form 20 January 2012 Accepted 23 January 2012 Keywords: Air pollutants Building insulation Emission factor abstract The effects of building insulation on ground-level concentration levels of air pollutants are considered. We have estimated regionally averaged reductions in energy consumption between 2005 and 2020 by comparing a business as usual with a very low energy building scenario for the EU-25. The corresponding reductions in air pollutant emissions were calculated using emission factors. Annual simulations with an air-quality model, where only the emission reductions due to insulation was accounted for, were compared for the scenarios, and statistically significant changes in ground-level mass concentration of main air pollutants were found. Emission reductions of up to 9% in particulate matter and 6.3% for sulphur dioxide were found in north-western Europe. Emission changes were negligible for volatile organic compounds, and carbon monoxide decreased by 0.6% over southern Europe while nitrogen oxides changed by up to 2.5% in the Baltic region. Seasonally and regionally averaged changes in ground- level mass concentrations showed that sulphur dioxide decreased by up to 6.2% and particulate matter by up to 3.6% in north-western Europe. Nitrogen oxide concentrations decreased by 1.7% in Poland and increases of up to 0.6% were found for ozone. Carbon monoxide changes were negligible throughout the modelling domain. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Benefits of increased building insulation are usually investigated in terms of economy (e.g. lowering of energy bills, generation of green collar jobs) and electricity supply (see e.g. Levy et al. (2003)). Reduced emissions of carbon dioxide have also previously been estimated (Jensen et al., 2009). However, the effects on the concentration level of criteria pollutants have not yet been esti- mated. In this study we attempt to include environmental benefits on shorter time scales and quantify the effect of insulation on air pollutant concentration levels in Europe. Increased building insu- lation leads to less energy consumption and thereby to reduced emissions of air pollutants and subsequently to decreased concentration levels. The purpose of the study was to estimate possible emission reductions and to evaluate whether there is a regionally averaged effect of insulation on ground-level air pollutants in Europe. We have focused on the main air pollutants in terms of adverse health effects comprising ozone, particulate matter, sulphur dioxide, nitrogen oxides and carbon monoxide. The period 2005 to 2020 was considered and realistic energy reductions due to insulation were estimated. Using average emission factors the energy reductions were recalculated in terms of emission reductions of primary pollutants. Annual simulations with an air- quality model with and without the emission reductions were compared in order to estimate the effect of the reductions on concentration levels. In order to isolate the effect of insulation only the emissions were varied between the 2005 baseline simulation and the 2020 reduced emission simulation, i.e. meteorological input to the 2020 simulation was that of the base year. Likewise, emission reductions due to the effect of energy and heat planning and policies in individual member states have not been considered here. 2. Emission estimation Energy savings from 2005 to 2020 due to insulation were calculated by comparing a business as usual (baseline) and an improved insulation scenario where very low energy buildings (VLEB) were assumed. The savings which related to different energy carriers used for space heating were assessed for the EU-25 countries as zone averages. The countries were divided into six zones each with their own climate characteristics: Zone 1: Finland, * Corresponding author. Tel.: þ45 39157439; fax: þ45 39157400. E-mail address: usn@dmi.dk (U.S. Korsholm). Contents lists available at SciVerse ScienceDirect Atmospheric Environment journal homepage: www.elsevier.com/locate/atmosenv 1352-2310/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2012.01.052 Atmospheric Environment 54 (2012) 393e399