A building physicist says townhouses and multi-unit buildings are most at risk of overheating.  

The Ministry of Business, Innovation and Employment says any detailed changes to fix hot homes need to avoid unintended consequences and require sector consultation.  

It told RNZ it won't be part of the Building Code review until 2031.  

Building Research Association's Stephen McNeil told Mike Hosking townhouses often have lots of floor-to-ceiling glass and can't ventilate properly.  

He says without proper glass treatment, like shading, these homes turn into greenhouses. 

McNeil told Hosking modelling should be used to understand how a house will perform. 

He says simple rules are needed, with uptake low for modelling despite being cheap at the design stage. 

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