I think some of the photoshop advice here is getting a bit complicated…
Anyway, here’s the process that I use…its not exactly what you’re asking but it migth give you a few tips or ideas.
First, model the basic house shape, and make sure you provide a bit of detail around any parts that you will be changing. This is because your VRAY render will need to provide reasonable shadows and reflections, otherwise it will look fake.
Essenially what you need to do is create a model of the house, but without the ivy, the existing windows that you are removing, and with the extra french doors, patio, and glass structure added.
To assist with this, you will need to create a few custom materials:
Main cladding material (stucco)
Brick material (lower cladding)
French doors.
You can do this using SketchUp (just import, trim and resize the photo, used as a material) , or if the materials are generic enough (like stucco or brick) you could download some seamless / repeating materials (or create your own). To help this process it would be handy to have a photo of the house straight-on (not on a perspective).
They dont have to be perfect, but should match as closely as possible in colour tone and lightness. For the french doors you can blend out the reflections first, otherwise theyll repeat and look fake.
The next step is to render it.
Then, use photoshop (or any simple photo editing app) to overlay the orginal photo on top of the render. Erase any bits of the photo that are changing and keep as much as possible of the original.
Then, using a Clone Stamp tool, borrow bits of the original photo and brush them around to add “roughness” and detail, and blend out the edges of your 3d model (it will be too blocky so the edges need to be softened a lot. Using layers (masks or erasing bits you dont need) will make this easier, particually around the ivy areas… These are simple tools and you dont need to worry about perspective etc.
In this particularly case, the area behind the glass structure will be difficult to edit afterwards so you would be best to create your render of the house Without the glass structure, then do a second render WIth the glass structure. Overlay the two images and erase out what you don’t need.
Filter (eg Add Noise) is a good idea, too… one of the most difficult bits of a photo edit is to match the “quality” of the image. Starting with a very high res image is helpful.
The final thing you need for realism is some reflections…can’t escape the fact that glass reflects everything about 8 times. This is by far better done using Vray. The easiset method is to take a photo FROM the house looking back at the landscape, wrap this inside a half-cylinder and put it behind the cemera as backdrop. You shoud also be able to download a basic “Sky dome” (environment Map) as well - Im not sure th eprocess in Vray ( maybe it’s got some built in feature) but this will add cloud and sky reflections to your glass…
This whole process sounds complex but it’s not really…you will have to become good at using the Clone Stamp tool (and lots of layers).
Some other brushes in photoshop /lightroom that work well are the Paintbrush with the mode changed to lighten/darken or hue or saturation. This is useful to adjust the tone of the image.
Good luck.
