I am a chemist rather than a dosemetric expert, but I do know something about this subject. I think you need to tell us more, what level of gamma radiation are you expecting. The methods I would choose varry greatly according to the expected dose rate.
I know some methods which would work in the microGy per hour range, and some which would work in the mGy per hour range. If you want to measure nGy per hour above the background then it will be hard.
I know at the other end of the scale Gy per hour that special tools are needed, one of the things which the Soviet army helped out with in the first days after the Chernobyl accident was dose rate measurements. They were using the doserate meters which were originally made for nuclear warfare purposes as these which the power plant were not suitable for measurements in such high radiation fields.
If you are going to get a dose of 100 at least microGy in one month then I would suggest using a TLD dosemeter of the type which is normally used on people. I would strongly suggest that you tell the dosemeter service that you are using the badge for radiation measurement for an experiment rather than a person. If they get a badge with 10 mSv on it then they might hit the roof if they think it was attached to a person.
If I recall rightly in Sweden that about 7 mSv over two months requires you to write a letter to the radiation protection board (SSM) explaining what you have done, while in the UK 15 mSv in one year will trigger an investigation by the state radiation protection authority into a worker.
So do stress to the TLD company that you are using the badges for something other than a person.
If you want the gross gamma dose then the TLD badge which I used to wear will give you the gamma dose to the core of the torso and it has a less filtered LiF lump which is for the skin dose.
If you want you can use metal filters to measure the high energy gamma without the low energy gamma, this is not a easy matter. If you want I can explain more.
You can find a number of articles on this topic in open literature. However, your study requires specific measurements to be inside the building. In the building materials , radon is usually present which emits gamma radiations and it is the cause radiation dose. You can use scintillation detectors for such measurements.
You can read famous book on Radiation Detection & Measurement by Knoll.
I guess you mean dosimetry of internally deposited radionuclides, including gamma-emitters. You should start with the ICRP Report 78 (1997) and NCRP report 84 (1985). ICRP task group 21 is currently revising internal dosimetry (http://www.icrp.org/icrp_group.asp?id=36). You can then look at more recent papers, depending on your specific problems. Good luck!
A quick overview of the Literature and the field of gamma radiation indoors and outdoors ay be found in the UNSEAR, NRPB and WHO reports. I attach here the last report from UNSCEAR that I downloaded recently.
We performed many years ago extended survey of indoor gamma dose rates with portable high pure Germanium detector . Find attach the corresponding publication .
Some work have been done in Nigeria with regard to measurement of natural background radiation in buildings either indoors or exterior of the building and may be available in literature.
I have no experencie with buildings, but I had expereince in indoor measurements in a mine. I think that the problem is similar, at least from the geometrical point of view. I could suggest to have a look to my paper and referrnces therein. Regards
Firstly, try to identify radioisotopes which are in walls, floor etc. You can do this with the use of measurements of energy spectra of gammas emitted by these radioisotopes. The high - purity germanium detector by ORTEC or another manufacturer can be applied in such measurements. You will be able to chose the measuring method better if you know emitters of radiation. The suitable literature you can find in SCOPUS.