We're in a large apartment with sliding glass doors facing west (lounge/dining and bedroom 2) and east (main bedroom, kitchen) each with a full length balcony/patio areas (4&5m deep and 6.5m wide). With this set up we get a fantastic cross breeze that cools down our entire home within minutes of the sliding doors being opened after a cool change arrives in summer. Our front (western) facing sliding doors get the hot afternoon sun so in summer we put up the outdoor umbrellas (soon to be outdoor awning blinds) that keep the sun off our windows and make entertaining out there more comfortable in the late afternoons reducing glare. We also find that we chase the sun/shade (depending on the season) when we're eating outdoors and entertaining so for summer, we use our western side in the morning where it's shady and cool and the eastern side of an evening and vice versa in winter. In the full length planter boxes on our western balcony we've put in rosemary which has grown up and provides a little extra protection against afternoon glare. We don't have air con and manage quiet well for the majority of summer exception of those two or three days each year that are super hot we close the whole apartment up, draw all the curtains and blinds, turn on the faithful Dimplex tower fan and resort to cool showers, salads and ice blocks.

@ Luke Buckle yep that’s the one. Has 1000w/200w switchable. I just put an oil heater in there 2 days ago to trial and room was toasty in under 5mibs WITH A non instant oil heater so a fan type wouldn’t take long. Also consider the heat lamps are 250w so 1000w total if all 4 are on. They feel like they are frying your head off from above when blazing all 4 lamps so depends on what “feel” you want also. As someone mentioned, let alone the cost of lamp replacement. Having been in lighting industry they wouldn’t last super long either (perhaps newer ultra violet do but their also pricier again)... I’m no better either!

any gas log fireplace should have very specific instructions for safe installation with measurements for distance from back and side walls, height above floor and height of any mantlepiece above the front of the heater and details of the correct method to enclose the flue..first check these instructions and then decorative finishes will be much easier to decide...if you haven't chosen your heater yet all the instructions should be available on line and this will also help decide the best heater for the space available

which size fireplace you choose will need to be decided by the available fireplaces to suit your needs (ie heating capacity, fuel, location of flue, overhead beams etc) so i'd start with the fireplace insert and then work all the other details from that..but, you should add scale sized furniture and suitable walking paths to the room so that the seating is angled to suit the view, the tv and the fire and you might find that the alcove with the bulkhead could be a better location for the TV and/or fireplace and storage wall