Time needed: 1 hour.
How to value your property for free
I would, of course, advocate getting a Bluebook valuer to perform this exercise, but if you want to get a ballpark estimate yourself, then, hopefully, this will give you a simple and basic approach.
The first think you need to do is to know the size of your property
So in order to determine the price of your property you need to see what the market paid for similar properties that sold that were in close proximity and also recently sold. Note the sale price and then divide by the size to get the cost / square meter. e.g €400k/100sqM = €4000 per sq/M. Do this for all the comparables you can find and then get an average of these so you get a cost/sqM for the area.
120sqM * €4000/sqm =€480k
South facing garden is desirable, large garden, gated parking, recently refurbished and in good condition and close to public transport, amenities, schools are all positive multiplies to a point as there is diminishing returns. Same goes for negative features being the opposite to the above.