Regarding winter requirements in oceanic climates, since the underheated period is not as severe, surface/volume and insulation standards are not as a rigorous as in cool temperate climates for example. Solar heat input in winter is desirable, so orientation and other considerations are the same as for cool temperate.
As overheating in summer is possible, structural sun control is necessary. Cut-offs between winter heating and summer sun exclusion depend on average monthly temperatures. Consider the use of deciduous vegetation for automatic shading discrimination between winter and summer.
As night temperatures are often below appropriate, even in summer, thermal mass is desirable. The thermal mass is, of course, also beneficial for passive solar design for winter. Summers are generally milder, with lower maximum and less frequent extreme days. Ventilation can cope with most summer overheating by removing the surplus heat. But if shading is adequate, such overheating should rarely occur. However, on a few extreme days, severe overheating may combine with elevated humidities to produce conditions worse than those in the tropics. On such days, additional care needs to be taken with reducing solar gain and air exchange rates, to limit the extent of internal temperature and humidity rises.

Location, siting and landscape

South facing slopes will significantly reduce available solar radiation, and ground surface temperatures may be reduced enough to maintain frost cover long into winter days. Slopes facing up to 40° west of north would be beneficial in winter, but severely aggravate summer sun exposure. Overall, north facing slopes, up to 20° east, are considered optimal. Planting should assure sun access in winter, to north elevations of buildings. Ideally, trees close to buildings would be deciduous, admitting winter sun and providing summer shade and evaporate cooling.

Building shape and orientation

Reduced surface/volume ratio of the building to minimize potential heat losses should be balanced against optimum planning for passive solar design. A rectangular compact plan of approximately 2:1 ratio is desirable, with the long axis oriented east-west. Two-storey designs improve the isolation of interior spaces from the external environment. 

External envelope

To reduce winter losses and summer heat gains, the building envelope should be insulated to high standards. Windows should be moderate in size, and double glazing will usually be justified on other than the northern orientation. Construction should be air-tight, compatible with the requirements for minimum ventilation. External doors and windows should be weather striped. Consideration should be given to simple heat exchangers to retrieve heat from exhaust air, to preheat incoming air.

Building mass

Though the building may not be continuously occupied, environmental conditions are expected to be maintained on a continuous, rather than intermittent basis. Therefore, there is an advantage in having an appropriate amount of internal thermal mass, to reduce the internal temperature swing to a minimum. A winter temperature swing of less than 4°C without supplementary heating should be considered an appropriate standard for the construction.
Thermal mass is a necessary component of passive solar design. It absorbs excess heat during the sunlit period, and returns it to the space at night. For maximum effectiveness, thermally massive elements should have a large surface area, and a thickness based on their optimum diurnal heat capacity. Thermal mass is also beneficial during the summer. During the day, it takes up heat from the interior, moderating any temperature rise. During the night, it can give up its stored heat to controlled ventilation.

Passive solar design

Where good winter sun is available, glazing should face the equator, with insulated shutters for control of conducted heat losses at night. However, except for areas separate from display and storage, conventional ‘direct gain’ solar collection is unacceptable.

Chapter 3 - Climate Responsive Modern Architecture