Yes, air-conditioning can mitigate. But what if the power supply fails? And if the power is generated with fossil fuels, it will only add to the problem.
It also takes a different style of housing/building construction (better isolation, smaller windows, and 'green' roofs) and city planning (more room for trees and vegetation, to improve evapotranspiration and create more shadow areas, and rainwater storage facilities). Urban Heat Island effects have a significant impact on local heat-stress conditions. It easily exceeds an additional temperature rise of 2- 5 degrees Celsius locally (or more near the dark surface of roads, so children and small animals/pets are even more affected).
Cheers,
Bart
Wouldn't smaller windows increase the need for more interior lights and electricity, thus adding to the problem? I like being able to not have to turn on any lights during the day. Granted my interiors are all painted white, but having large bay windows really helps.
Now insofar as the modern move in housing and building construction, it is a double edged sword that can have some pretty bad side effects. For starters, since buildings are made so much more air tight then before, indoor air quality is worse then what it use to be. It is even the case that with modern office buildings you can no longer open the windows. Even though we have come a long way in HVAC technology, it still does not replace a nice breeze bringing in fresh air.
On top of that, tighter built houses require a significantly higher build quality, which not all contractors will master, since moisture gets trapped inside the walls and does not evaporate out. This will lead to rot in many cases, and, even with properly built homes, it can be difficult to avoid. In my house, which was built in the 1920s, my joists sit directly in masonry joist pockets on top of the brick. Having wood on brick/stone goes against all logic since brick/stone releases moisture, causing rot. But since my house is not completely air tight, this moisture dries out before rot can set in and my near 100 year old joists are all in great condition.
Masonry joist pockets are now against code due to how air tight houses are required to be built today. So work arounds are devised, such as using treated rim joists sitting on the foundation with metal joist hangers. But even here, treated wood eventually rots and replacing a rim joist is no easy task.
Insulation too can have bad effects on facades, especially masonry ones. Although most houses no long use masonry baring walls, many have masonry facades, which absorb moisture. Problem though is that moisture trapped in stone during a freeze thaw cycle will cause micro cracks in the masonry material, leading to failure over time. Fortunately, heated bricks/stones hold less moisture, so if your house is not insulated, you have nothing to worry about since the heat will force the moisture out. However, unless you have closed cell spray foam directly on the inner side of the masonry wall, insulating an exterior masonry wall will lead to eventual failure. You cant prevent moisture from being drawn into the wall from convection currents that naturally form during the winter, even with a moisture barrier. Moisture barriers only protect from moisture dispersion, which only accounts for about 5% of moisture entering into the interior wall.
(FYI, if you have masonry baring wall, never insulate them except with
closed-cell foam.)
I feel like with some of these modern building techniques, we are getting more efficient heating and cooling at the expense of the need to preform major maintenance projects more often. On top of that, many contractors are just being trained in modern techniques and materials, some of which can not be used with older houses. For instance, my foundation is schist stone, which is a softer stone. Modern mortar mixes use a 3:1 ratio of sand to Portland cement and this cures to being harder then schist, and many pre-WW1 stone/brick. You never want the mortar to be harder then the stone, since it will cause the wall to eventually fail, so you need to use a more dilute mix.
Although many masons know that mortars need to be softer then the stone, nearly all available modern stones/bricks are harder then the standard mortar mix. So in many cases, it never crosses their minds to use a more dilute mix if they are working on an older house.
