I your house masonry or "sticks and cardboard"? If sticks and cardboard, is the insulation in walls backed with metal foil? You'll have a lot better chance of getting a signal through the walls if the construction is sticks and cardboard without metal foil. A window in the desired direction can help a lot. I have done the following (temporarily).
Make a corner reflector antenna for your wireless access point. Make it from three sides of a large cardboard box lined with kitchen foil. Sit the Access Point on the bottom of the corner on the bisector of the other 90-deg angle. Unlike a flat plane reflector, the exact distance from the corner is not critical - but I would choose between a quarter and a half wavelength, say 3 to 6 cm.
I hope that your access point has an external antenna, since that makes placement a lot more straightforward.
See picture. The corner is far larger than needed.
