The article describes typical apartment buildings built in Swedish residential areas in the ‘50s, ‘60s and 70's. Each of these buildings included calculations on the effects and investment cost of a number of renovation measures aimed at improving energy efficiency. By applying multi-criteria decision making methods Simple Additive Weighting (SAW), Multiplicative Exponential Weighting (MEW) and Complex Proportion Assessment (COPRAS), the preferences of building owners regarding renovation measures were studied. The study highlighted four important criteria, including the use of energy from district heating and electricity, investment cost and payback period. The owner preferences were found to have a major impact on the outcome of the study. These owners gave sufficient weight to renovation measures within a short payback period. Renovation actions falling out to be quite attractive are additional thermal insulation in the attic and heat recovery from exhaust air. Santrauka Straipsnyje išnagrinėti trys tipiniai švedų daugiabučiai, pastatyti 6-ajame, 7-ajame ir 8-ajame dešimtmečiais. Buvo atlikti kiekvieno šių pastatų atnaujinimo priemonių skaičiavimai, įvertinantys efektyvumą ir investavimo apimtis, kuriomis siekiama didinti energijos vartojimo efektyvumą. Taikant daugiakriterinius sprendimo priemimo metodus, tokius kaip Simple Additive Weighting (SAW), Multiplicative Exponential Weighting (MEW) and COmplex PRoportion Assessment (COPRAS), buvo tiriami savininkų teikiami prioritetai pastatų atnaujinimo priemonėms. Tyrimas buvo atliekamas vertinant keturis pastatų kriterijus: energija, vartojama centralizuotam šildymui, ir elektros energija, investicijų sąnaudos ir atsipirkimo laikotarpis. Atlikus skaičiavimus buvo nustatyta, kad didelę įtaką tyrimo rezultatams daro savininku nuomonė. Šie savininkai daugiausia demesio skyrė trumpam renovacijos priemonių atsipirkimo laikotarpiui. Viena patrauklesnių renovacijos priemonių yra papildoma šilumos izoliacija palėpėje ir šilumos gavimas iš ištraukiamo oro.

Sweden has a large multifamily housing stock that was built between 1960 and 1975. An important current issue is how this stock can be renovated in a sustainable way. The article analyses a strategy used by a suburban municipal housing company that had clear social ambitions and offered the tenants three options of renovation: Mini, Midi and Maxi. Most tenants chose the Mini alternative which meant that they could afford to stay and that there was no increase in costs for the social authorities. An investment analysis showed that the Mini alternative had a positive net present value, but that the Midi and Maxi alternatives were more profitable. Even though there was no clear environmental focus in the renovation, energy use was reduced by 8%. As a conclusion, the study shows that a sustainable renovation is possible but that there are a number of conflicts between the different dimensions of sustainability.

Crowding in dwellings is an important public health issue. We hypothesize that overcrowding may cause indirect health effects by adversely affecting the dwelling itself, for example, by increasing dampness leading to mold. We therefore performed a systematic search and a scoping review on overcrowding leading to dwelling condition characteristics of relevance for health. A literature search was performed using the PubMed and Scopus databases up to 5 March 2021. The search yielded 100 records with relevant information. We found that overcrowding is defined in numerous ways and often address “socially deprived” populations. Six studies report associations of overcrowding with at least one dwelling condition characteristic, namely lead, cadmium, microorganism distribution, dust mite and cockroach allergens in dust, cockroach infestation, peeling paint, and mold. One of the studies reports associations between several characteristics, e.g., association of mold with cleanliness and rodent infestation, and points out the common use of pesticides. Additional characteristics were extracted from the remaining 94 records, without data on statistical associations with overcrowding. Our review suggests that multiple potentially hazardous dwelling condition characteristics often coincide in overcrowded dwellings. The epidemiological attribution of health effects to any characteristic is therefore difficult. Causal relationships are even more difficult to establish, as overcrowding is also associated with a range of social and other circumstances that may affect health. The complexity should be considered by scientists and practitioners dealing with overcrowding in dwellings.